Future developments of motorized traffic and fatalities in Asia

Future developments of motorized traffic

and fatalities

in

Asia

Future developments of motorized traffic and fatalities in Asia

Revised version of the paper presented at the Conference on ASian Road Safety 1993 (CARS 93), Kuala Lumpur, Malaysia, 25-28th October 1993

D-93-22 M.I. Koomstra Leidschendam, 1993

SWOY Institute for Road Safety Research P.O. Box 170 2260 AD Leidschendam The Netherlands Telephone 31703209323 Telefax 31703201261

FUTURE DEVELOPMENTS OF MOTORIZED TRAFFIC AND FATALITIES IN ASIA

Koomstra. Matthijs J.

[SWOV Institute for Road Safety Research. P.O. Box 170. 2260 AD Leidschendam.] [Road Safety Lecturer. University of Technology. Delft.]

THE NETHERLANDS

ABSTRACT

Long tenn developments in trafft: growth and in fuality rate can be mther well described by non-linear functions of time. The functions are a S-shaped curve for saturating traffic growth (kilometrage or motorized vehicles) and an exponentially decreasing curve for fatality mte. both modulated by a cyclic wave function with a long period. The product of traffic growth and corresponding fatality rate detennines the level of road safety. Therefore. reduced fatalities only can be observed if the fatality mte decreases more than the traffic grows. The model analyses for highly motorized countries have shown that the momentary slope of the decreasing fatality rate is delayed dependent on t~ slope of the cyclic modified S-shaped trend in trafft: growth. This relation between traffic growth and fatality risk is theoretically understood as evolutionary growth and risk adaptation of technological system growth under deterring and accelerating socio-economic influences. The genemlity of the evolution model for motorized traffic and its remarkable fit to data are illustrated by the analyses of long time-series on kilometrage. fatality mte and fatalities for the USA and

Japan. National different developments are interpreted as differences in onset time. speed and modulation of the national road transport evolution and its inherent risk adaptation. For some South East Asian countries the growth of motorized traffic is accelemted by socia-economic changes. while its cyclic modulation may express economic upsurges ~d depressions. For other Asian countries an accelemted traffic growth is absent or far delayed. Quantitative data analyses are also shown for Malaysia (as a newly fast developing South-East Asian country) and Pakistan (as a slow developing Asian country). If accelemted traffic growth is not accompanied by a compensating risk improvement the result is a disastrous development of road safety. as the prognoses for Japan. Malaysia and notably for Pakistan show. Thoughts are given to means which may prevent such worse safety outcomes of traffic growth. The possibilities for success are limited. unless investments in road safety are given an as high priority as provisions for traffic growth.

INTRODUCTION

The developments of road safety and motorized mobility over long periods of time in many countries recently have been analyzed and successfully modelled on the basis of models for time-dependent macro-system growth and risk adaptation by Oppe and Koomstra (Oppe. Koomstra & Roszbach. 1988; Oppe &

Koomstra. 1990; Oppe. 1991a; Oppe 1991b; Koomstra. 1992a). Highly motorized countries show that the percentage of growth in vehicle kilometres is relatively large and nearly constant in the starting phase of the motorization process. but also show that this percentage diminishes in the later motorization phases. Since the growth of kilometrage can not be infUlite it must be assumed that the total kilometrage eventually has to reach a saturating level. These assertions leads to a S-shaped growth curve. The so-called logistic function is such a S-shaped curve which fit the long tenn time series for motorized vehicle kilometres of many highly motorized countries rather well. This is illustrated in figure 1 by the development of the annual kilometrage in the USA from 1923 to 1990. which 68 years constitute the longest time-series available for any country.

The growth of motorization. however, is accompanied with the serious adverse development of road safety. In the USA and the countries of North West Europe the number of annual road fatalities has increased to a maximum somewhere around the early seventies and levelled off thereafter. The explanation of the rise and fall in fatalities has troubled researchers for a long time. The reason for that single peaked macroscopic development of fatalities, however, can be easily understood if one recognizes that the fatality rate. that is the annual road fatalities per annual kilometrage. tend to decrease by reduction percentage which fluctuates around a constant percentage. This implies an exponential decay function for the fatality mte development.

a

Veh.km.10 70000 60000 50000 40000 30000 20000 10000 a Observed -Predicted

USA

[ S - curve only ) 9 Max. Veh. Km.· 7800 x 10

Figure 1. The S-shaped development of kilometrage in the USA.

As an illustration of this macro-trend in the fatality rate we show in figure 2 the observed annual fatality rates in the USA for the same time-series of 68 years as well as the fitted exponential decay function. As a consequence somewhere in time the fatality rate reduction becomes larger than the diminishing growth rate.

Fatality rata

USA

veh.

.10 8 11 a 2 10 a a 9 a 8 7 _a 8 1 5 1980 1970 1980 1990 4 3 a Observed 2

Predicted

1

[ expo

decay

only ] 0

1920

Before that point in time the number of fatalities will increase and thereafter decrease. because the product of the macroscopic trend curves of vehicle kilometres and fatality rate gives by defmition the development of fatalities. Therefore. nothing else than these two monotonic developments in traffic growth and fatality rate is needed for the explanation of a single peaked development in fatalities. as observed in a macroscopic sense for many highly motorized countries (Oppe. 1991a). The long term macroscopic developments in traffic growth fatality rate for the USA are quite well described by the curves of S-shaped growth and exponential risk decay. Their product is the resulting macroscopic curve of fatalities in the USA. which necessarily is a single peaked curve. In Figure 3 we display the observed time-series of annual road fatalities in the USA from 1923 to 1990 and its macroscopic prediction by the product of the fitted curves from figure 1 and 2.

Fatalities

60000 50000 40000 30000 20000 1()(X')O a a a

USA

,.: ... .. •••• D /aaoDaOD .' a a ... a D ~ j a

~

ita! ~J a

Observed

.... "

.Pred. Rate x Obs. Veh. Km.

-

Pred. Rate x Pred. Veh.

Km.

O~rrrrmm~rrrrmm~mmmm~mm~mmmm~mmmm~mmmm~mmmmrrrrmr 1~1~1~1~1~1m1_1~~

Figure 3. The development and macroscopic trend prediction of fatalities in the USA.

Although the macroscopic trend in fatalities is described by the product of the underlying satisfactory trend curves. the resulting curve does not retrospectively predict the annual numbers of fatalities accumtely. The marked deviations of observed fatalities are by closer inspection due to a lagged correlation in observed devi

-anons from the underlying two macroscopic curves (differences in figure 3 between the observations and the dotted line are due to fatality rate error and between the dotted and solid line to kilometrage error).

Theoretical Background

Our analyses for many highly motorized countries have shown that the development of fatalities is largely dependent on the past history of motorization growth in a country. Countries with a relative long and more or less uninterrupted history of mass motorization growth. like the USA and Great Britain. show nowadays the lowest fatality rates. The analyses of developments in many other countries have also shown that the fatality rate decreases slower the less steep the traffic growth curve is. In fact Oppe (1991a) has shown that slope parameter of the fatality rate curve tend to have a value which is about half the value of the slope pammeter of the traffic growth curve. Moreover. if this relation holds for an S-shaped growth (logistic function) and a constant decay of the fatality rate (exponential function) then. so Koomstra (1988) proved. the level of fatalities is only dependent on the derivative of the traffic growth and not on its absolute level. A relation between the speed of traffic growth and the decay speed of the fatality rate can be understood as growth and adaption in a technological system evolution. With growmg economic possibilities people will buy more and more cars and travel more and more by car. while companies increasingly deliver their goods by vans and trucks. Individuals will use their cars not only for business and home-work trips. but also for

social and tourist trips and more so the more the economic situation improves and leisure time increases. This growing road transport of individuals and goods asks for an enlarged, improved and well maintained road infrasbUcture. In democratic countries such a renewed and enlarged road infrasbUcture will be established by the pressure of the voting people and lobbies. because they favour road transport in growing economies of democratic countries. The authorities have to provide that infrasbUcture in order to fulfil the democratic needs on the one hand and on the other hand to make economic growth possible. In modem tenns the systems of free market economy, transport and democracy constitute a self-organizing macro-system (Jantsch, 1980) in which these submacro-systems pull and push the evolution of road transport (Koomstra.

1992a). Under the condition that the resources are available the course of the macro-system evolution leads more or less autonomously to a growing road transport for persons and goods. This growth leads to renewal and enlargement of the road infrasbUCture which consists of better and safer roads than the already existing infrasbUcture, while also the replacement of transport means by new and safer cars, the increasing mean driver experience and the enhancement of traffic regulations and their enforcement leads to relative more road safety. In this way the decrease in fatality rate can be understood as an adaptation process which speed is dependent on the speed of growth in road transport. Generally the safer risk adaptation will be delayed with respect to the growth of road traffic, due to the time needed for planning and design as well as for decision taking on several levels and last but not least for actual (re)consbUction and implementation. Such an adaptation delay with respect to mobility growth can explain the lagged correlation between the deviations from the macroscopic curves for traffic growth and fatality rate.

THE MODEL WITH CYCLIC MODIFICATIONS

Although the underlying macroscopic developments in vehicle kilometres are mainly described by a saturating S-shaped curve and the development of the fatality rate by an exponential decay curve, economic developments may deter and accelerate these evolutionary developments in traffic growth and fatal risk adaptation. Analysis of data from several countries has shown that the deviations from the underlying macro-trend curves can be modelled by a single long tenn cyclic modification of the macroscopic curves. The devi-ations from the S-shaped traffic growth in the USA are described by a cyclic main pattern with a period of 18 years. Figure 4 displays the observed annual kilometrage and its prediction from the analysis of the S-curve with this cyclic modification for the USA in the period after World War

n.

Veh.

1rP

70000 60000 50000 40000 30000 20000 10000 0 1945 Q

Observed

-Predicted

USA

with cycle 18 years

Max. Veh.

Km.

•

7800 x 109

Figure 5 shows the cyclic modified decay curve for the post war development of the fatality rate in the USA.

Fatality rate

V .km.10 8

4

USA

a

Observed

Predicted

3

with cycle 18 years

2

1

O~~~nT~~nT~~nT~~nT~~nT~~nT~~~~~Tr

1945

Figure 5. Exponential decay curve with cyclic modifications of fatality rates in the USA.

The product of these cyclic modified curves yields the prediction of the fatalities in the USA in figure 6.

Fatali ies

50000

,

o /a',. a,~.D I o a,' I, _ I 1 ~ 'f 1

.

~ ,

•

USA

40000 a • ,6·a,,'&'\?rI~ ~ a

;,

30000 20000 10000 D

Observed

. --- Predicted with cycle 18 years

Prad. Rate x Obs. Veh.

Itm.

-

Prognosis with cycle 18 years

Prea. Rate

x

PraCt. Veh.

km.

O~~~~~nT~~~~~~~~~~~~~~~~~~~~

1945 1955 1965 1975 1985 1995 2005

The srune cycle period as for the traffic growth curve governs the deviations from the exponential decay curve of the fatality rate, but that cycle has a delay of a quarter of the period compared to the cycle around the S-shaped growth curve. This is not only consistent with the evolutionary and lagged relation between kilometrage growth and risk adaptation, but also with the theoretical derived result that the fatality rate is dependent on the derivative of the in versed growth function (Koomstra, 1992a). It means that a periodic larger increase in traffic growth is preceeded by a partial overlapping stagnation in the decrease of the fatality rate and vice versa. The smaller intermediate peaks besides the macroscopic single main peak in the curve of the fatalities for the USA are the result of such combinations of partial overlapping periods of increased traffic growth and stagnated decrease in fatality rate. The retrospective prediction based on the cyclic modified curves is much more accurate (s.d. error percentage of kilometrage

=

2.36% and mean Chil-deviation of fatalities due to fatality rate error is 81.1, compared to 13.5% and 336.0 for the analysis without cycle). The validity of this evolutionary model of traffic growth and risk adaptation has shown to be quite satisfactory in the analyses of time-series of data from many other countries. Therefore, it may serve also as a prognostic method for future developments in road traffic and safety. The model has been used for prognoses of traffic growth and road safety in Central-East European countries (Koomstra, 1992b).

ROAD TRAFFIC AND SAFETY DEVELOPMENTS IN ASIAN COUNTRIES

In this section we show the results of the model analyses for some Asian countries as examples of the different typical developments in the Asian continent In particular: Japan as an already full developed COWltry, Malaysia as a newly fast developing country and Pakistan as still slow developing country. Model Analysis for Japan

The results from the same analysis as illustrated for the USA is presented for Japan in figure 7 for the growth of road traffic and in figure 8 for the fatality rate, where the optimal period of the main cyclic modification of both macroscopic curves turned out to be about 36 years. The figures show the analysis over the period from 1951 to 1990 for which kilometrage data are available. Note that the underlying S-curve has its largest increases in the beginning eighties, but that cyclic modification has just there its maximal

reduction and replaces the actual largest increases to the late sixties and the beginning nineties.

Veh. Km.1r1

10000 9000 8000 7000

eooo

5000 4000 3000 2000 1000

JAPAN

., Observed

__ Predicted

Max. Veh.

Km. -

957 x

HP

O~~~~~~~~~~~~~~~~~~~~~ 1950

Fatality rate

V&h.krn.10

8 70 60 50 30 20 10 1 1

JAPAN

D

Observed

-Predicted

1~~~~~~TO~~~~~~~~~-r

1965

1970

1975

1980

₁₉₈₅

1990

O~~~~~~~~~~~mm~~~~~

1950 1960 1970 1980 1990 2000

Figure 8. Observed and predicted fatality rates in Japan.

The actual fatalities and their retrospective and prospective prediction by the product of the curves from figure 7 and 8 are shown for Japan in figure 9. The two periods of relative larger growth and the partial overlapping cycles of somewhat stagnated decay in the fatality rate causes two peaks in fatalities for Japan.

Fatalities

_JAPAN

18000 a Observed

... Predicted

16000 Prad. Rata X Obs. Vah. km.

14000 - P::snoSIS P . Rata x Pred. Vah. km.

12000 aD 10000 8000 a

6000

4000 2000 0 1950 1960 1970 1980 1990 2000

The comparison between the USA and Japan illustrates several theoretical aspects of the model. Firstly, it illustrates that the fatality rate is dependent on the kilometrage development The annual reduction of the fatality rate in the USA is in the mean just above 3% and in Japan nearly 8%, but the speed of growth in Japan is also about 2.5 times higher than in the USA. Secondly, it shows that the fatality level is delayed dependent on the level of the increase in kilometrage and not on its absolute level. Therefore, Japan shows two main fatality peaks around the first half of the seventies and the mid nineties just after the two periods of largest kilometrage increase due to the delayed influence on the decay in the fatality rate caused by preceeding relatively reduced traffic growth periods. For the same reason, but differently phased, the USA shows a single flat maximum level modulated by smaller peaks between 1970 and 1990. Last but not least the start of the developments for the USA lies far before World War

n,

while for Japan it lies just thereafter.

Many analyses have shown that the mechanisms are the same, only the developments for different countries are phased differently in time. The development in the USA starts about 30 years earlier, but also is relative to its maximum slower. than in North-West continental Europe and Japan. The deterred Central-East

European developments can be seen as about 25 years lagged with respect to North-West Europe (Koomstra, 1992b). In that way the developments in newly industrializing Asian nations can be imagined as lagged in comparison to Japan by 25 years, which for Malaysia is demonstrated in the sequel.

Model Analysis for Malaysia

For Malaysia we use in the analysis of the growing road traffic the data of the number motorized ve'tlcles (including motorized two- and three wheel vehicles) from 1962 to 1989 as published by the IRF (1966-1991) annually, because as for most Asian countries we do not have long time-series of kilometrage available. This period of 28 years is too short for a reliable estimate of the saturating maximum level from the data. The increased motorization growth around 1980 and its levelling off thereafter can be seen as a part of the curvature of a S-shaped growth with a relative low maximum level of saturating motorization as well as a periodic influence of a cyclic modification of S-shaped growth with a much higher indeterminate maximum level. The former interpretation leads to an optimal model fit by a maximum level of only 6 million motorized vehicles and a cycle period of 22 years. This maximum seems at face value an improbable low level of future motorization for an industrializing Malaysia with now about 60 million inhabitants. Figure 10 displays this improbable result as well as an alternative one for which we assumed the maximum to become in the end the same as the implicitly predicted maximum for Japan of 1.5 motorized vehicle per inhabitant.

Veh.

X

1000

35000 30000 25000 20000 15000 10000 5000

Malaysia

• Observed - Predicted

1 • max. veh.: 1.5 per lnh. 2 • optimal fit to obs. data

Max. VBh.

e

mill. 2 cycle period 22 year

o~~~~~~~~~~~~~~~~~~~

1980 1970 1980 1990 2000 2010

Figure 10. Observed motorized vehicles in Malaysia and their alternative prognoses.

Year

The time-series of fatalities for Malaysia contains before 1971 data which are differently defined (death on the spot) than the data from 1971 onwards (period prolonged until death). It is uncertain how these values relate. Their ratio in Japan is 1.33. but in Thailand it seems 2.1 (Somnemitr. 1986). Therefore. the analyses of the fatality rates of figure 11 and fatalities in figure 12 are only based on data from 1971 to 1989.

Fatality rate

per

1,000

veh.

Malaysia

2 1.6 1.2

0.8

, , " D

Observed

Predicted

without cycle

--- Predicted

with cycle period 18 year

0.4

... _"

",

--

_---

---

O~~TO~~TOrn~Trrn~Trnn~rrnn~rrnn~-~-r-n--n-~-T-~-rr--1970 1980 1990 2000 2010 2020

Year

Figure 11. Observed and predicted fatality rates (per veh.) in Malaysia and their prognosis.

Fatalities 4000

Malaysia

3000

2000

1000

/

D!~

•• ' "~D

I

D . ... .

/"

i

~/

1.

..:-A

_.'

l

D' D

Observed

- - Predicted Model 1

pred.

rate x obs. veh .

.

.

.

.

.

•

Predicted Model 2

pred.

rate x

obs.

veh.

-Prognosis

pred.

rate

x

pred.

veh.

1 - Max. Veh. 40 mill.

cycle 18 year 2 - Max. Veh. 6 mill.

cycle 22 year

O~~~~~~~~~~~~~~~~~~~~Trrn~~rr

1970 1980 1990 2000 2010

2O~ear

The cycle period of 22 year which optimally fits the motorization growth with the low level of maximum motorized vehicles. does not contribute additionally to the exponential decay function of the observed fatality rate. Without cyclic modification of the exponential decreasing rate the observed fatalities are not satisfactory predicted (mean ChP-dev.

=

14.2; Model 2. dotted line in figure 12). An optimal cycle modification of the decay curve with a cycle period of 18 year improved that prediction significantly (mean Chi2-dev.

=

5.1; Model 1. intermined line in figure 12). Therefore. the cycle period for the fitted alternative prognosis with the high maximum motorization level of 40 million motorized vehicles was taken to be also 18 years. The former alternative (Model 2) with the low motorization maximum and a traffic growth cycle of 22 year shows only one marked peak in the increase of motorization in the late seventies. As a consequence of this model for the Malaysian developments we also predict a delayed single peak in fatalities around the mid-eighties with an ever decreasing number of fatalities thereafter. The other alternative (Model 1) with a maximum motorization level of 40 million motorized vehicles and a 18 year cycle for both curves predicts after the relative large motorization increase of the late seventies again a comparable large motorization increase in the first half of the nineties and due to the 18 year of the cycle period again such an extra increase around 2010. The middle extra increase is relatively large because of its upward cyclic modification of the macroscopic trend is located just before the largest increase of the underlying S-shaped curve. The later extra increase is relatively smaller because then the growth has already reached two-third of its maximum and the underlying S-shaped curve has passed its inflexion point Due to the lagged cyclic stagnation of the decrease in fatality rate. which partially overlap with the cyclic extra increases of

motorization growth. a second peak of nearly 3900 fatalities is predicted by this model in the later half of the nineties as well as the flfSt peak of over 3600 fatalities around the mid eighties. In the next century the prognosis for the percentage of traffic growth is always smaller than the predicted percentage of decrease in fatality rate (for Malaysia in the mean 6.5%). Therefore. the prognosis for the next century shows an ever decreasing number of fatalities in Malaysia to less than 500 after 2025.

Although the short time-series for Malaysia do not permit a reliable estimation of model parameters. the model based on a maximum level of 40 million motorized vehicles and a cyclic influence on motorization growth and fatality rate with a period of 18 year yields an excellent prediction of fatalities over 19 past years (note that this period also holds for the cycle of the USA and is half of the cycle period for Japan).

Moreover. the validated relation between growth and adaptation supposes that the observed steep decay of the fatality rate in Malaysia is only consistent with a high mean growth rate. Since the economic growth in Malaysia give also no reason for the assumption that the maximum level of motorization for Malaysia should be less than for Japan. one is inclined to trust the outcome of the model with these parameters (Model 1 in figures 10 and 12) to some degree. If this is correct. the fatalities in Malaysia will rise again in this decade. Unless the fatality rate reduction is enhanced by an extremely effective road safety policy or traffic growth is effectively controlled for lower increases or both developments are successfully influenced simultaneously. this temporary pessimistic safety prognosis has to become a reality in Malaysia

Model Analysis for Pakistan

Also for Pakistan no time-series on annual kilometrage of motorized vehicles is available to our knowledge.

However. the National Transport Research Centre of Pakistan (NTRC. 1987; 1992) has published consistently defmed data on annual road fatalities from 1947 onwards and annual numbers of all types of motorized vehicles from 1956 onwards. In the sequel these data from 1956 to 1991 are analyzed by our model for motorization growth and risk adaptation. As for Malaysia also here the numbers of motorized vehicles are taken to include motorized two- and three wheel vehicles. because of the relative large shares 0 f

these vulnerable types of motorized road users (in 1991 47.5% for Pakistan and for Malaysia 43.2% in 1989). The vehicle data before 1956 are not used since their level is neglectable small (especially for pass uger cars which probably will constitute a major part at the end of the motorization growth). while also no data on fatalities are then available. The series of 36 year allow a relatively stable estimation of cycle and S-curve parameters. but a reliable separation of S-curve and long term cyclic influences is still limited ( the observed time-series must be longer than the cycle period). The optimal fit of the motorized vehicles yields a slow growth curve with a relative low maximum of 4.15 million (approaching 4 million around 2020) and a main cycle with a period of 28 year. Probably this main cycle is a combination of harmonic cycles of 18 year and 36 year periods. but we have not fined the model for two or more cycles since it increases the number of parameters and decreases the stability of parameter estimation. The fatality rate. however. showed a marked cyclic influence of a cycle with a period of 36 years, the same period as the cycle for Japan. This inspired an alternative analysis of motorized vehicle growth with a 36 year cycle and a prior fixed maximum

of 77 million motorized vehicles, which as for Malaysia is based on the Japanese maximum of 1.5

inhabitants per motorized vehicle. The observed data as well as the retrospective and prognostic results of the optimal and alternative solutions for motorization growth are displayed in figure l3. Figure 14 shows the observed and predicted fatality rates, the latter modified by a cycle with a period of 22 year or 36 year.

Veh. X 1000 40000

Pakistan

2000

35000

1500 30000 1000 25000 500 20000 0 15000 1855 1970 a Observed 10000 _{- Predi'ied} max. pycle:

5000 1 -2 • optimal

confOrm

tfrad.

it to obs. data J~

0

1955 1965 1975 1985

1985

1995 2005

Max. Veh. 4.15 mill. cycle period 28

y.

2

Figure 13. Observed and predicted motorization growth in Pakistan and its alternative prognoses.

Fatality rate

10 p.103veh. 9 8 7 6 5 4 3 2 1 1955 a 1965

Pakistan

1975 1985 a Observed -Pred~ed

with cycle period 36

y.

--

--- Predicted

with cycle

per'bd

28

y

.

1995 2005

...

_.

_...

... '".-

.

.

.

-~ .. ,

2015

Figure 13 clearly show that the cyclic modification of the underlying main trend curve fits better for a cycle period of 28 years in case of motorization growth (dashed curve 2 of inserted part of figure 13). while figure 14 shows a cycle period of 36 year in case of the fatality rate (solid curve of figure 14). Figure 14 also clearly demonstrates that the cyclic influence dominates over the underlying exponential decay curve in the development of the fatality mte in Pakistan. In effect the underlying exponential decay is characterized by a relatively low annual reduction percentage of only about 3%. that is two to three times slower than for Malaysia or Japan. In our technological evolution theory with its relation between traffic growth and risk adaptation this low decay of fatality risk is only consistent with relative low mean growth mte. Also the economic developments in Pakistan until now do not justify a motorization growth which is comparable to Japan. Therefore. it is questionable wether a growth to a maximum of 77 million motorized vehicles is a realistic scenario. But even in that scenario the motorization in Pakistan is still more than 25 years delayed compared to the prediction for Malaysia with a comparable high maximum. Nonetheless also a development to the extremely low maximum of 4.15 million motorized vehicles (25 inhabitants per motorized vehic cs) is already disastrous for the development of fatalities in the next decade for Pakistan as figure 15 demonstrates.

Fatalities

_Pakistan

50000 5000 45000 40000 35000

30000

25000 20000 15000 10000 5000 Predicted by

pred. rata x obs. vah. D 3000

1000

o~~~~~~~~~~~~~~~

1955 '970

a

Observed

-

Predicted max. veh.

n

mill.

cycle 38 year

---- Predicted max. veh. 4.15 mill.

cycle 28 year

1985

aaDaaaa D

Prognosis by

pred.

rata

x pred.vah.

caDDD

DDaaDaaD

o~~~aTaDMD~aTaa~a~a~aD~~~~~~~~~~~~~~~~~~~~~

1955

1985

1975

1985

1995

2005

Figure 15. Observed and predicted fatalities in Pakistan and their alternative prognosis.

In this figure we simply display the observed fatalities and the results of the product of the corresponding model curves of figure 13 and 14. since by defmition it yields the predicted fatalities. From figure 15 we see that independent of the high or low motorization scenario the fatalities will rise up to more than 12000 in the year 2000. Since Pakistan had 5289 fatalities in 1991 it anyhow means a more than 100% increase of fatalities within the next lO years. If the high motorization scenario is adopted for Pakistan the future of road safety seems even more disastrous. It results in a maximum of more than 50 thousand fatalities annually around the year 2020. which is about ten times the momentary level! In case of the scenario of a low maximum motorization level the fatalities will start to drop in the next century to about 4300 in 2018 and rise again thereafter to nearly 7000 mainly due to the large cyclic influences on the fatality rate in Pakistan. Long term predictions are always uncertain. However. if the past 36 years are well predicted by a for other countries validated model which only transforms the perfect predictable variable of time. it is not unlikely that the next ten years can be prospectively predicted fairly reliable. The main problem for Pakistan is the relatively low mean reduction in the overall fatality rate. With reference to figure 14 one may argue that the cyclic development of the fatality rate. which cycle mainly explains the drop before 1976. is of no

the rate of the last 17 years a better basis for its extrapolation. Although then one would ignore more than half of the available data and surely would grossly misjudge the backward prediction of the fatalities before 1975. it would yield a much more optimistic prediction for the future development of the fatalities. Anyhow the annual reduction percentage in the fatality rate should become larger than the corresponding percentages of increase in motorization growth in order to prevent an increase in fatalities. If such is not achieved the fatalities in Pakistan will again rise as it has over the 30 years before its fluctuating level since 1986·

ST RuCTURAL ROAD SAFETY IMPROVEMENTS

One lesson from these road safety prognoses must be that we should control the growth of road traffic, but for economic reasons and especially in democratic countries with a free market economy the traffic growth is very hard to influence. The other lesson is the only alternative for a positive development in road safety: the improvement of the annual reduction in fatality rate. Although it is not the aim here to review the effects of road safety measures some structural ways for policies of road safety improvement may be in place.

Transport Types

Motorization changes the road system drastically, but the road system has never been designed in such a way that the accident opportunity is prevented a priori like it has been for rail- and air-transport. Rail and air passenger transport are more than 200 times safer than European and surely also Asian road transport.

Table 1. Risk per transport mode.

mode road rail air area Eur. Comm· West Eur. USA

fatality rate p. pass. km

3.5xlO-8

1.6xlO-10

O.4xl()"IO

Some Asian countries used to have a relatively well developed rail system and in view of the need of a safe transport it is important to maintain and enhance that mode of passenger transport An increased share of passenger transport by train will also help to control the growth of road traffic and it may prevent partially the problems of increasing congestion in the future. while it certainly contributes to overall transport safety.

Since road users of two -wheel motorized vehicles have a many times higher fatality risk a road safety policy under growing motorization must be directed to a reduction of the share of motorized two-wheel (and three-wheel) vehicles. The reduction of its large share in many Asian countries surely contribute much to a higher reduction of the fatality rate. if economic growth allows for its replacement by modem safe cars.

Road Types

Despite the gradual upgrading of the road system it everywhere still is a network of roads which constitutes a concatenation of a nearly endless variety of road sections by an also endless variety of cross-connections. The result is a road system which

is

too complex for the road user to allow reliable predictions for the next oncoming situation. Only the modem motorfreeways permits relative reliable predictions. Since this road category is relative well predictable and also because the variation in speed is relative low (extra shoulder lane for emergency stops. no level junctions and no opposite and only motorized traffic) it is a relative safe type of road. in spite of the high speeds driven. A comparable high level of safety holds for residential calming areas, where speeds are so bw that speed variation between all road I\sers is also low. As can be seen from the next table of injury and fatal ity rates on Dutch roads, all other road types than motorways and calming areas have considerable highe'r rates . '!be lack of safety varies with the COmbination of the level of speeds and the amount of variation in speeds due to discontifll"'ties (~ve~l junctions and opposite traffic) and mixture of slow and fast categon-es of road users on the road type -The rural roads have the highest fatality rate and the urban arterials the highest injUry rate· Although for As\m countries such detailed data are not available the applicable rates will be higher because the Netherlands has one of the

Table 2. Injury and fatality rates for road types in the Netherlands 1986.

Road type Max. Mixing Level junctions Injury rate Fatality rate

km/h fast/slow Opposite traffic mill. km 100 mill. km

...

---

--- --- -...

-

... -... -...

-

-- --- .. _ ...

--

...

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-

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-calming area < 30 yes yes 0.20 < 0.3 resid. street

SO

yes yes 0.75 1.2 urban arterial

Sono

yes/no yes 1.33 2.5

rural road 80 yes/no yes 0.64 4.6

rural motor road 80 no yes 0.30 2.1

rural motor road 100 no no 0.11 1.7

motorfreeway 100/120 no no 0.07 0.5

world's most safe road networks (total fatality rate per 100 million km. of 1.7 in 1986 and 1.3 in 1992). However, the difference pattern probably will be comparable for road types in Asian countries.

A large modem motorfreeway network in the fast developing Asian countries will not only be necessary for reasons of the increasing road transport needs, but it also will redistribute the traffic towards this safer road type and away from the dangerous ruraI roads. This in itself would have a large positive effect on the reduction of the national fatality rate. The road safety in built-up areas could be improved markedly by the construction of by-pass roads around villages and towns for the otherwise trough-going traffic. The road safety in residential area itself can benefit tremendously by the consistent introduction of traffic calming areas with priority for non-motorized traffic and pedestrian zones in towns and large villages. Dutch evaluation research has even shown that calming areas can reduce 90% of the injury accidents in the area and Table 2 shows in comparison to residential streets a nearly 75% reduction in injury rate. The redesigning of the road categories between motorways and residential calming areas to a limited number of categories of self-explaining roads with well predictable uniform layouts of routes and crossing types for an orderly and safe traffic flow is also most urgent. This is the major long term task which should be undertaken in a natio

-nal coordinated way. since diversity between regions contributes to unpredictability. Infrastructural separation of slow traffic(non-motorized or low motor capacity) and traffic of fast (high motor capacity) or t\mvy

vehicles is one of the safe design principles which should be applied where possible also in Asian countries.

This means pedestrians on sidewalks only and preferably cyclist (and may be low motor capacity two and three wheelers) on separated paths (or lanes). Safer road constructions and a reordering of traffic for these vulnerable road users can very much improve the fatality rate reduction. especially in Asian countries with a high share of non-motorized road users. Research with respect to crossings has shown that the British roundabout with priority for roundabout traffic is a much safer level crossing than non-signalized as well as signalized junctions. Reductions even of 90% of injury accidents have been observed after reconstruction of junctions to roundabouts. The relative low share of fatal car-car accidents in the UK may be explained by the frequency of roundabouts in the British road network. There is a long way to go before such a renewed and safe road system will be established. The flfSt step is conceptual: a functional hierarchy of categorized and homogenized roads in the network. The second. the clarification of its safety principles on a national level by the preparation and dissemination of reference material with all the safety principles for an upgrading to the safest-possible road network. The last step is the building of new roads and the improved maintenance and reconstruction of the existing roads according to these safety principles.

Road User Bebaviours

Driver education is a prerequisite. but different driver licensing requirements have not shown that road safety 'IS influenced by these differences. The risk for new drivers is high. but drops the more kilometres are driven

,U\l only stabilizes on a lower risk level after more than fifty-thousand kilometre experience. Apparently safe driving can only be learned by much practice. Only prolonged learning periods in easier circumst.'mces and under the accompany of experienced drivers (by means of a graded licensing with curfew laws and prolonged accompanied driving before full licensing) have shown to have positive effects on road safety. Information campaigns on road safety. especially those which are not directed to specific concrete behaviours and/or are not sustained by intensified police enforcement. are only temporarily or not at all effective. Lack of seat belt wearing, overspeeding and drunken driving, however. are the main behavioural areas where road safety can be improved effectively. Seat belt wearing has shown to have an effect of about 40% on the n'sk

of a fatal outcome from a car accident (Evans. 1991). The level of blood alcohol while driving has shown to have an exponential increase on the risk of casualty accidents. as the often confmned study of Borkenstein (Evans. 1991) has shown. For example the fatality risk with 1.2 promille blood alcohol is about 6 times higher than for sober drivers. The proportional reduction of the mean speed has a double quadratic effect on the proportional reduction of fatalities (Nilsson. 1982). This means that a 10 % reduction in mean speed (0.9) will have a 35% reduction in fatalities (0.1J4=0.65) Also speed differences are parabolic related to the risk of accidents (Solomon. 1964: Cirillo. 1968). Mean speed is more related to the severity of accident outcomes and speed variance to the frequency of accidents. Adequate speed reduction and homogenization of speeds are both very important for road safety. Because of the relation between the speed distribution (mean and variance) and road safety and the expected increasing share of modem fast passenger cars in fast developing

Asian countries the speed limits for their roads in built-up areas and rural roads should not exceed

respectively SO and 80 krn/h. Intensified efficient police enforcement by automatic devices (speed violations) or by visible controls of randomly selected road users on unpredictable places and times (driving under the influence of alcohol) and combined with targeted information campaigns have shown (Koomstra, 1992b) that safety can be improved markedly. Large effects on the reduction of fatalities are observed in Australia if the intensity level of enforcement becomes above one out of three license holders controlled annually.

CONCLUSION

Prognoses of road safety for Asian countries are rother annoying. National. regional and local efforts for an effective road safety by infrastructural road safety improvements. prolonged driver training and intensified police enforcement of appropriate road safety laws as well as the promotion and offering of other safer types of transport can not only reduce the predicted immense loss of human lives and the sorrow over them. but also save the waste of the huge costs involved. In the EC the costs of the lack of road safety are estimated to be 70 billion ECU. Investments in road safety pays off more than usually is assumed.

LITERATURE

-Cirillo, J.A. (1968). Interstate system accident research study 11. Public Roads 35: 71-75. - Evans, L· (1991) Traffic safety and the driver. Van Norstrand Rheinhold. New York. - IRF (1966-1991). World Road Statistics. International Road Federation, Geneva - Jantsch, E. (1980). The self-organizing universe. Pergamon Press, Oxford.

- Koomstra. M.I. (1988). Risk reduction as a learning process. Second approach in: Oppe. S:. Koomstra, MJ. & Roszbach. R. (1988).

- Koomstra, M.I. (1992a). The evolution of road safety and mobility. lATSS Research. 16: 129-148. - Koomstra. M.I. (1992b). Long-term requirements for road safety: Lessons to be learnt. Paper OECD

Seminar on "Road Technology Transfer and Diffusion for Central and East European Countries", Budapest. -Nilsson, G. (1982). The effect of speed limits on traffic accidents in Sweden. VTI-report no: 68, S -58101

p.: 1-10. Linkoping.

- NTRC (1987). Analytical review of road and road transport statistics [1947-'85]. Nat Transp. Res. Centre, Government of Pakistan.

- NTRC(1992). Transport Bulletin: Road Transport (1982-1991). Nat Transp. Res. Centre. Government of Pakistan.

- Oppe, S. (1991a). The development of traffic and traffic safety in six developed countries· Accid. Anal. &

Prev. 23: 401-412.

-Oppe. S. (1991b). Development of traffic and traffic safety: Global trends and incidental fluctuations· Accid. Anal. & Prev. 23: 413- 422.

- Oppe, S.: Koomstm. M. J. & Roszbach, R. (1988). Macroscopic models for traffic and traffic safety. Three related approaches from SWOV. In Conf. Proc~ Tmffic safety theory research methods. Session 5: Time

dependent models· SWOV. Leidschendam.

-Oppe. S. & Koornstra, MJ. (1990). A mathematical theory for related long term developments of road traffic and safety. In: Koshi. M. (Ed.). Transportation and traffic theory; p. 113-132. Elsevier. New York· -Solomon. D. (1964). Accidents on main ruml highways related to speed. driver. and vehicle. Fed· Highway

Adm. Rep .• US Dep. of Transp .• Washington DC.

-Somnemitr. T. (1986). Road Accident prevention in Thailand. In: Traffic Planning and safety. Pro c. 1 3th