PROMETHEUS and DRIVE:
`Their Implications for Traffic Managers
`
`DR W J G i l l a n
`Transport and Road Research Laboratory
`Old Wokingham Road, Crowthorne, Berks, R G l l 6AU
`United Kingdom
`
`( D r G i l l a n i s t h e i n t e r n a t i o n a l coordinator o f t h e PRO-GENERAL component
`o f t h e PROMETHEUS programme)
`
`Abstract
`
`PROMETHEUS and DRIVE are major European i n i t i a t i v e s .
`They share t h e common o b j e c t i v e s o f applying
`advanced technology t o t h e reduction o f road accident
`r i s k and t h e improvement o f t r a f f i c e f f i c i e n c y .
`The
`c e n t r a l theme o f PROMETHEUS i s t h e i n t e l l i g e n t co-
`p i l o t ;
`t h e programme i s focussed on systems which a i d
`t h e d r i v e r d i r e c t l y w h i l e DRIVE concentrates on t h e
`Hence t h e programmes are
`i n f r a s t r u c t u r e o f systems.
`complementary.
`This paper discusses t h e background
`t o these programmes and examines t h e i r p o t e n t i a l impact
`on road throughput.
`It concludes t h a t t h e changes
`due t o DRIVE w i l l mainly come from t h e a p p l i c a t i o n o f
`dynamic r o u t e guidance and information systems and
`are l i k e l y t o be evolutionary;
`those due t o PROMETHEUS
`could increase t h e maximum e f f e c t i v e throughput o f
`roads by between twenty and several hundred per cent
`but major problems remain t o be solved.
`1.
`
`I n t r o d u c t i o n
`
`PROETHEUS i s an acronym f o r 'PROgraMme f o r European
`T r a f f i c w i t h Highest E f f i c i e n c y and Unprecedented
`It began i n 1986 when eleven major car
`Safety'.
`manufacturers agreed t o work together t o explore t h e
`p o t e n t i a l o f advanced e l e c t r o n i c and computing tech-
`nology f o r improving road s a f e t y and t r a f f i c e f f i c i e n c y .
`The European Commission (EC) was also considering
`a programme w i t h s i m i l a r o b j e c t i v e s and i n 1987 pro-
`posed the DRIVE (Dedicated Road I n f r a s t r u c t u r e f o r
`Vehicles i n Europe) programme.
`It took some time
`t o draw up t h e f i n a l programme o f work f o r DRIVE and
`research commenced i n January 1989.
`
`Both PROMETHEUS and D R I V E are l a r g e programmes w i t h
`complex objectives.
`This paper o u t l i n e s t h e research
`programme o f both p r o j e c t s and discusses t h e p o t e n t i a l
`impact i n one o f t h e c e n t r a l areas, t r a f f i c manage-
`ment.
`
`2.
`
`PROMETHEUS
`
`PROMETHEUS i s one o f t h e
`2.1
`PROMETHEUS
`l a r g e s t p r o j e c t s w i t h i n t h e EUREKA framework.
`EUREKA
`was established i n 1985 by t h e m i n i s t r i e s respons-
`i b l e f o r i n d u s t r i a l research and development w i t h i n
`19 European countries,
`i e , i t i s not sponsored by
`t h e EC.
`The o b j e c t i v e was t o promote c o l l a b o r a t i v e
`R and D between companies i n two o r more countries.
`There are now almost t h r e e hundred EUREKA projects,
`ranging from t h e development o f high d e f i n i t i o n t e l e -
`v i s i o n t o medical diagnostic k i t s .
`Financial support
`f o r EUREKA work comes,
`i n t h e main,
`from t h e m i n i s t r i e s
`responsible f o r i n d u s t r i a l research and development
`w i t h i n t h e p a r t i c i p a t i n g countries.
`There i s no
`c e n t r a l budget;
`a l l p a r t i c i p a n t s must seek t h e i r
`own f i n a n c i a l support.
`The l e v e l o f support a v a i l -
`able t o p a r t i c i p a t i n g organisations varies from country
`t o country, but i s t y p i c a l l y between about 20 per
`cent and 70 per cent o f t h e r e l e v a n t costs o f t h e
`i n d u s t r i a1 p a r t i c i p a n t s .
`@ Brltldr Crown Copytight
`
`PROMETHEUS i s l e d by a Steering Committee which has
`representatives from v e h i c l e manufacturers from f i v e
`A t present they are BMW,
`European countries.
`Daimler-Benz, Porsche, Vol kswagen and MAN (West
`Germany), F i a t ( I t a l y ) , Matra, PSA and Renault
`(France), SAAB and Volvo (Sweden) and Jaguar and
`Rolls-Royce (UK).
`
`Most EUREKA p r o j e c t s are aimed a t developing equip-
`ment o r a process which w i
`l
`l lead d i r e c t l y t o a new
`PROMETHEUS i s d i f f e r e n t .
`Competition
`market.
`between v e h i c l e manufacturers i s always f i e r c e and
`i t would have been extremely d i f f i c u l t t o promote
`near market research i n such a diverse group.
`It
`i s also aimed a t exploring t h e p o t e n t i a l benefits
`o f applying a broad range o f new technology t o areas,
`such as road safety, which are o f general community
`i n t e r e s t and not j u s t r e s t r i c t e d t o v e h i c l e manu-
`Hence one o f t h e e a r l i e s t ,
`f a c t u r e r s and purchasers.
`and most important, decisions taken by t h e PROMETHEUS
`Steering Committee was t h a t t h e research should be
`pre-competitive and t h a t c o n t r i b u t i o n s o f research
`and ideas should be r e c r u i t e d widely from a range o f
`A t t h e
`U n i v e r s i t i e s and Research Laboratories.
`end of 1987,
`towards t h e end o f t h e p r o j e c t d e f i n i t i o n
`phase, other i n d u s t r i a l partners from t h e v e h i c l e
`equipment suppliers and component manufacturers were
`i n v i t e d t o j o i n t h e programme.
`A l l o f these partners
`w i
`l
`l remain w i t h t h e programme u n t i l i t s scheduled
`completion i n 1993.
`
`The d i f f e r e n t methods o f supporting research w i t h i n
`t h e countries w i t h partners i n PROMETHEUS makes i t
`d i f f i c u l t t o estimate t h e funding a v a i l a b l e f o r t h e
`However more than t h r e e hundred
`programme.
`s c i e n t i s t s and engineers now p a r t i c i p a t e i n t h e work.
`
`PROMETHEUS i s a l a r g e
`2.2 Research Framework
`R and D programme spread over f i v e c o u n t r i e s and
`w i t h about 60 p a r t i c i p a t i n g organisations.
`The
`research straddles a whole range o f technologies
`and t h e r e are many i n d i v i d u a l components, each w i t h
`This d i v e r s i t y makes
`i t s own subset o f objectives.
`i t extremely d i f f i c u l t t o manage as one l a r g e p r o j e c t .
`Over i t s l i f e i t has evolved i n t o a range o f sub-
`p r o j e c t s w i t h numerous cross l i n k s t o ensure t h a t
`The
`i n f o r m a t i o n and ideas are exchanged e f f e c t i v e l y .
`whole p r o j e c t i s managed by the Management Steering
`Committee, which has representation from each o f
`t h e p a r t i c i p a t i n g v e h i c l e companies.
`
`The c e n t r a l concept o f PROMETHEUS i s t h e i n t e l l i g e n t
`c o - p i l o t , an i n t e g r a t e d set o f systems t o a i d and
`enhance t h e c a p a b i l i t y o f t h e d r i v e r .
`Although t h e
`development w i
`l
`l provide some o f t h e f u n c t i o n s r e q u i r e d
`f o r f u l l y automatic d r i v i n g t h a t i s not t h e objective;
`t h e technical problems and doubts about t h e fundamental
`need f o r such a system r u l e i t out f o r t h e present.
`The c o - p i l o t concept allows t h e development o f a
`number o f functions which can be developed and
`i n t e g r a t e d i n t o on-vehicle systems w h i l e s t i l l s a t i s -
`f y i n g t h e requirement t h a t t h e d r i v e r i s i n charge.
`
`237
`
`Petitioner Nissan North America, Inc. - Exhibit 1015 - Page 1
`
`

`
`The i n i t i a l i n d u s t r i a l programme w i t h i n PROMETHEUS was
`divided i n t o three broad areas, PRO-CAR,
`PRO-NET and
`YRO-ROAD.
`Within these sub-programmes eleven
`thematic p r o j e c t s ' were developed, each concerned
`w i t h development i n one area o f technology.
`I n
`a d d i t i o n t h e companies are developing a number o f
`demonstrator projects;
`t h e aim w i t h these i s t o
`provide 'technology p u l l ' which w i
`l
`l c l a r i f y t h e
`important developments needed w i t h i n the thematic
`projects.
`
`A t an e a r l y stage i n the development o f PROMETHEUS i t
`was r e a l i s e d t h a t many o f t h e ideas and concepts being
`discussed could not be r e a l i s e d by t h e available tech-
`nology.
`There was a need f o r inputs o f basic research.
`Four sub-programmes were established t o s a t i s f y t h i s
`need:
`they are PRO-CHIP (custom integrated c i r c u i t s
`and advanced sensors), PRO-ART ( a r t i f i c i a l i n t e l l i g e n c e
`(comm-
`and advanced signal processing) and PRO-COM
`unications technology).
`The f i n a l group was i n i t i a l l y
`known as PRO-GENERAL but t h i s has now been abbreviated
`the aim o f t h i s group i s t o b r i n g e x i s t i n g
`t o PRO-GEN;
`t r a f f i c management and road safety expertise i n t o
`t h e programme.
`The o v e r a l l s t r u c t u r e of PROMETHEUS
`and the l i n k s between sub-programmes are shown i n
`Figure 1.
`
`The PRO-CAR programme i s p r i m a r i l y
`PRO-CAR
`2.3
`which are wholly contained
`concerned -stems
`w i t h i n the vehicle.
`I f described i n terms o f the
`i n t e l l i g e n t c o - p i l o t system they are systems f o r
`Systems being
`enhancing the senses o f t h e d r i v e r .
`framework include:
`examined w i t h i n t h e PRO-CAR
`
`A n t i - c o l l i s i o n systems;
`these t y p i c a l l y use microwave
`o r o p t i c a l radar systems which w i l l monitor t h e road
`ahead and g i v e warnings o f p o t e n t i a l hazards.
`Usually
`the outputs from these w i l l merely r e i n f o r c e t h e i n f o r -
`however
`mation the d r i v e r sees i n t h e scene ahead;
`some parameters, such as c l o s i n g v e l o c i t i e s , are
`d i f f i c u l t f o r d r i v e r s t o estimate and mechanical measure-
`ment could provide valuable additional information.
`
`these would improve v i s i -
`Vision enhancement systems;
`b i l i t y by providing some c a p a b i l i t y o f seeing using
`i n f r a - r e d o r u l t r a v i o l e t l i g h t w i t h appropriate sensors
`and displays i n t h e car.
`
`these measure the c o e f f i c i e n t
`Road surface sensors;
`o f f r i c t i o n between the t y r e and the road t o determine
`the l i m i t s o f adhesion and warn t h e d r i v e r i f he
`I d e a l l y d r i v e r s need t o know about
`approaches them.
`conditions up t o about lkm ahead which means t h a t
`advanced systems o f t h i s type would include comnunica-
`t i o n s equipment t o r e l a y the information back along
`a t r a f f i c stream.
`
`t h e PRO-CAR work includes d r i v e r
`Driver Monitors;
`monitoring, normally by analysing t h e p a t t e r n o f steer-
`i n g corrections and c o n t r o l movements and detecting
`when t h e performance i n d i c a t e s h i s a b i l i t i e s are
`impaired, possibly due t o being over-tired.
`
`The dominant theme i n these PRO-CAR systems i s improving
`road safety, p r i m a r i l y f o r t h e d r i v e r o f t h e vehicle.
`However they i n t e r f a c e d i r e c t l y w i t h the way t h a t he
`c o n t r o l s t h e vehicle and determining whether they w i l l
`produce a r e a l reduction i n accident r i s k i s a d i f f -
`i c u l t task.
`It demands an understanding o f d r i v e r
`behaviour, and an appreciation o f how he w i
`l use the
`l
`features provided by t h e new system;
`f o r example a
`v i s i o n enhancement system might have l i t t l e impact on
`accident rates, o r even a negative impact, i f d r i v e r s
`elected t o d r i v e more q u i c k l y when v i s i b i l i t y i s poor.
`The systems must be studied by assessing d r i v e r reaction,
`both i n simulators and when d r i v i n g t e s t vehicles.
`
`Hence a v a r i e t y of thematic research p r o j e c t s are
`needed f o r PRO-CAR, extending w e l l beyond the basic
`technical development o f systems.
`The relevant
`p r o j e c t s are:
`- Sensors and signal processing;
`- Actuating Systems and Vehicle operation;
`- General architecture ( i e , systems a r c h i t e c t u r e ) ;
`- Man-Machine I n t e r f a c e and;
`- Vehicle safety and system dependability.
`2.4 PRO-NET
`PRO-NET systems depend on commun-
`i c a t i o n l i n k s w e e n vehicles.
`A t t h e simplest
`l e v e l t h i s communication l i n k can be used merely t o
`pass information from one vehicle t o another;
`f o r
`example t h e f r i c t i o n information derived by t h e PRO-CAR
`sensors.
`However once communication l i n k s are i n
`place i t becomes a t t r a c t i v e t o use them t o pass basic
`information about the speed o f t h e vehicle.
`It
`i s also r e l a t i v e l y straightforward t o engineer them t o
`measure the separation and t h e r e l a t i v e bearing o f
`adjacent vehicles.
`Hence w i t h i n the memory o f a
`PRO-NET processor i n a vehicle i t i s possible t o
`b u i l d up a model o r ' p l a n ' o f t h e position, separation,
`r e l a t i v e bearing and r e l a t i v e v e l o c i t y o f a l l vehicles
`on t h e adjacent s t r e t c h o f road.
`This i s p r e c i s e l y
`t h e information t h a t a d r i v e r has and uses t o c o n t r o l
`h i s vehicle.
`
`The f i r s t step i n PRO-NET developmeyt i s t o produce t h e
`system which w i
`l permit t h i s 'plan
`t o be computed
`l
`and maintained i n r e a l time as vehicles drive;
`the
`next i s t o examine how i t can be used t o a i d t h e
`d r i v e r i n ways t o reduce accident r i s k and improve
`A t f i r s t t h e o b j e c t i v e i s To develop
`t r a f f i c flow.
`computing systems which process t h i s ' p l a n
`t o derive
`information which can be presented t o t h e d r i v e r
`b u t beyond t h a t i t may be possible t o i n t e r f a c e i t
`d i r e c t l y w i t h t h e vehicle controls.
`
`The thematic p r o j e c t s which are mainly concerned
`w i t h PRO-NET systems are:
`- PRO-NET system engineering;
`- Communication f o r PRO-NET and PRO-ROAD and;
`- Emergency warning systems.
`
`I n p r i n c i p l e PRO-NET
`PRO-NET Safety Systems
`2.5
`systems could have an impact on road safety.
`I f
`t h e ' p l a n ' processor i n t h e vehicle detects t h a t
`adjacent vehicles are moving w i t h a v e l o c i t y and
`t r a j e c t o r y t h a t means t h a t a c o l l i s i o n i s l i k e l y
`i t can warn t h e d r i v e r o r even assume l i m i t e d control
`o f t h e vehicle t o avoid t h e accident.
`
`Assessing t h e p o t e n t i a l impact o f PRO-NET systems i s
`T y p i c a l l y over 90 per cent o f accidents
`d i f f i c u l t .
`can be ascribed t o a temporary f a i l i n g i n d r i v e r s
`and are p o t e n t i a l savings f o r PRO-NET systems.
`I n
`r e a l i t y t h e system t o prevent many o f those would
`demand a system of higher c a p a b i l i t y and r e l i a b i l i t y
`than t h e d r i v e r ;
`i t r e t u r n s t o t h e problem t h a t
`i t i s impossible w i t h i n t h e foreseeable f u t u r e t o
`develop a system w i t h t h e c a p a b i l i t i e s o f a human
`being .
`A methodology f o r guiding t h e development o f t h i s
`type o f safety system and assessing t h e p o t e n t i a l
`I n the
`b e n e f i t s i s being developed w i t h i n PRO-GEN.
`
`Petitioner Nissan North America, Inc. - Exhibit 1015 - Page 2
`
`

`
`past several European c o u n t r i e s have conducted i n -
`depth on t h e spot analysis o f road accidents,
`T y p i c a l l y
`these were based on having an expert team on standby
`which was c a l l e d out when a serious accident was
`reported t o t h e p o l i c e .
`I n France and West Germany
`researchers are examining t h e records from these i n -
`depth analyses and asking t h e question "What t y p e
`o f PROMETHEUS system f u n c t i o n would have been needed
`t o avoid o r minimise t h e impact o f t h i s t y p e of
`I n some cases i t i s c l e a r t h a t nothing
`accident?".
`could have been done;
`i n others t h e r e are c l e a r
`i n d i c a t i o n s t h a t some o f t h e p o s s i b l e f u n c t i o n s o f
`PRO-NET might have helped.
`Sometimes d e t a i l e d research
`work i s needed on computer simulations.
`Eventually
`t h e i n t e n t i o n i s t o b u i l d up a d e t a i l e d p i c t u r e o f
`t h e i n c i d e n t s t h a t might have been prevented by a
`workable PRO-NET system;
`t h e numbers o f these can
`then be scaled up u s i n g n a t i o n a l accident s t a t i s t i c s
`t o p r e d i c t t h e expected b e n e f i t .
`The i d e a l would
`be t o i d e n t i f y a s e t o f system f u n c t i o n s which would be
`useful i n minimising a range o f i n c i d e n t types.
`
`There are problems which need t o be addressed i n t h e
`research associated w i t h PRO-NET.
`One i s t h e p r a c t i c -
`a b i l i t y o f developing an i n t r o d u c t i o n strategy;
`w i l l
`t h e system be e f f e c t i v e i f o n l y a few vehicles on
`t h e road are equipped o r i s i t v i t a l t h a t a l l vehicles
`have working equipment?
`The second i s t h e problem
`o f b r i n g i n g vulnerable road users, such as pedestrians
`i n t o t h e system so t h a t i t s b e n e f i t
`and c y c l i s t s ,
`i s n o t r e s t r i c t e d t o h i g h speed special roads.
`One
`p o s s i b i l i t y i s t o issue them w i t h a simple l i g h t w e i g h t
`transponder b u t t h e p r a c t i c a b i l i t y of
`t h i s approach
`i s open t o question.
`F i n a l l y t h e r e i s t h e question
`o f how d r i v e r s would use t h e system;
`i f they drove
`w i t h l e s s care a f t e r i t s i n s t a l l a t i o n t h e b e n e f i t s
`could be negated.
`
`The other major area where extensive research would
`be needed i s t h a t being assessed w i t h i n t h e Vehicle
`Safety and System Dependability thematic p r o j e c t .
`p r a c t i c a l PRO-NET system might e v e n t u a l l y i n t e r f a c e
`w i t h primary c o n t r o l s o f vehicles, such as t h e accel-
`e r a t o r , brake and p o s s i b l y even steering.
`Any f a i l u r e
`would have major consequences and t h e probabi 1 i t y
`A f a i l u r e
`of causing an accident would be high.
`might occur i n t h e hardware, t h e software o r i n t h e
`o v e r a l l system structure;
`reducing t h e j o i n t prob-
`a b i l i t y o f a l l f a i l u r e modes t o an acceptable l e v e l
`i s a major task.
`
`A
`
`It i s i n s t r u c t i v e t o examine t h e f a i l u r e r a t e o f t h e
`e x i s t i n g d r i v i n g process.
`The UK has a v e h i c l e popula-
`t i o n o f 22 m i l l i o n and t h e r e are 5,000 road deaths
`each year.
`The average journey distances and speeds
`i n d i c a t e an average v e h i c l e usage o f about 350 hours
`each year.
`Hence t h e MTBF (mean t i m e between f a i l u r e )
`of
`t h e present d r i v e r v e h i c l e system can be evaluated
`as 1.5 m i l l i o n hours f o r f a t a l accidents.
`This i s an
`extremely high f i g u r e i n comparison w i t h most conven-
`t i o n a l engineering systems.
`Those t h a t achieve it,
`such as j e t a i r c r a f t o r nuclear power plants, have
`extensive f a u l t monitoring and r e p a i r by expert teams.
`If PRO-NET were t o be successful t h e acceptable increase
`i n r i s k o f a f a t a l accident due t o system f a i l u r e s
`might need t o be t e n times t h i s f i g u r e ,
`i e , a MTBF
`of 15 m i l l i o n hours.
`It remains t o be seen whether
`figures o f t h i s order are possible.
`
`2.6 PRO-NET and Road Capacity Road capacity
`i s l i m i t e d by t h e way t h a t d r i v e r s judge separation
`from t h e v e h i c l e i n f r o n t and a d j u s t the gap i n l i n e
`Capacity could be improved i f
`w i t h road conditions.
`these behavioural c o n s t r a i n t s were modified.
`
`Modifying behaviour t o improve capacity could have an
`
`impact under a v a r i e t y o f road operating conditions,
`i n c l u d i n g :
`(i) Flow breakdown as a high speed road nears
`On most p a r t s o f t h e network t h e
`s a t u r a t i o n flow.
`capacity i s determined by j u n c t i o n capacity.
`However
`t h e capacity on h i g h speed roads, u s u a l l y w i t h grade
`separated junctions, can be determined by t h e capacity
`o f t h e l i n k i t s e l f .
`As t h e t r a f f i c f l o w increases
`per hour
`t o around 2000 pcu (passenger c a r u n i t s )
`per lane on unobstructed roads speeds drop and v e h i c l e
`concentrations increase u n t i l t h e d r i v e r s have t o
`use brakes as w e l l as accelerator t o maintain h i s
`The appropriate
`separation from t h e v e h i c l e i n f r o n t .
`r e g i o n i n t h e speed f l o w r e l a t i o n s h i p , c i r c l e d i n
`speeds
`Figure 2,
`i s characterised by unstable flow;
`o f t e n f a l l t o low l e v e l s and t h e r e i s s t o p - s t a r t
`d r i v i n g , p a r t i c u l a r l y i n regions downstream from
`I n a PRO-NET system where vehicles are
`j u n c t i o n s .
`aware o f t h e p o s i t i o n s and v e l o c i t i e s o f adjacent
`vehicles t h e r e are a number o f p o s s i b i l i t i e s f o r
`improving capacity.
`
`The f i r s t approach would be t o assume l i m i t e d c o n t r o l
`If v e h i c l e speeds were
`o f t h e v e h i c l e accelerator.
`maintained as t r a f f i c flows increased up t o and beyond
`2,000 pcu per hour per lane t h e i n t e r v e h i c l e gap
`would n o t reduce t o t h e same extent and t h e onset
`o f breakdown could be h e l d o f f .
`For example t h e
`t y p i c a l speed f l o w r e l a t i o n s h i p shown i n Figure 2
`i s
`i t i n d i c a t e s
`based on measurements on t h e M6 motorway;
`t h a t speeds drop from 105 km/h a t low f l o w s t o about
`75 km/h a t mean flows o f 1900 vehicles per hour j u s t
`before t h e onset o f f l o w breakdown.
`I f breakdown i s
`assumed t o be s o l e l y determined by t h e gap t o t h e
`v e h i c l e i n f r o n t maintaining t h e speed a t t h e low f l o w
`value would increase t h e breakdown threshold f l o w from
`1,900
`t o 2,650 vehicles per hour per lane, an increase
`o f 40 per cent.
`
`This system resembles an i n t e l l i g e n t c r u i s e c o n t r o l .
`A t t h e onset o f f l o w breakdown d r i v e r s would be t r a v -
`e l l i n g a t s i g n i f i c a n t l y higher speeds and would have t o
`brake even more sharply than would normally have
`t h e breakdown w i
`l
`l be even more abrupt
`been t h e case;
`This could be overcome i n p a r t by a l s o
`than usual.
`l i n k i n g t h e PRO-NET processor t o t h e brakes o f t h e
`T y p i c a l l y d r i v e r r e a c t i o n times before
`v e h i c l e .
`braking are i n t h e 0.3 t o 1 second time i n t e r v a l (11,
`and towards t h e t o p end o f t h a t f i g u r e i f he i s
`basing h i s judgement on a d i f f i c u l t parameter, such as
`t h e c l o s i n g speed and distance t o a v e h i c l e i n f r o n t .
`The PRO-NET c o n t r o l l e r could e l i m i n a t e t h i s r e a c t i o n
`time and produce a smoother t r a n s i t i o n from t h e f r e e
`f l o w i n g t r a f f i c conditions t o breakdown.
`
`Instead o f
`Other c o n t r o l s t r a t e g i e s are possible.
`h o l d i n g speeds a t t h e low f l o w l e v e l t h e system could
`i n t e r a c t w i t h t h e d r i v e r t o allow lower i n t e r - v e h i c l e
`gaps before h i s r e a c t i o n s cause breakdown a t lower
`speeds.
`The mean i n t e r - v e h i c l e gap a t breakdown i s
`approximately 31m i n t h e example shown i n Figure 2;
`if t h e operation o f PRO-NET allowed vehicles t o operate
`w i t h an i n t e r - v e h i c l e gap o f 20m a t speeds o f 60 km/h
`t h e breakdown capacity f i g u r e would move t o 2,400
`vehicles per hour per lane, a 26 per cent increase
`i n maximum throughput.
`
`Hence PRO-NET could, i n p r i n c i p l e , increase capacity
`Much
`o f a h i g h speed road by up t o 40 per cent.
`research needs t o be done t o determine whether such
`systems are r e a l l y f e a s i b l e .
`This includes research
`i n t o t h e c o n t r o l algorithms embedded i n t h e processor
`The l a t t e r are p a r t i c u l a r l y
`and i n t o t h e MMI aspects.
`c r i t i c a l since f o r p a r t o f t h e time, a t l e a s t t h e
`equipment would be operating t h e c o n t r o l s i n a manner
`
`239
`
`Petitioner Nissan North America, Inc. - Exhibit 1015 - Page 3
`
`

`
`The t r a n s i t i o n
`counter t o the d r i v e r s i n s t i n c t s .
`from automatic t o manual control would be p a r t i c u l a r l y
`d i f f i c u l t as would the problem o f ensuring he was
`confident t h a t he could always over r i d e the system.
`The system r e l i a b i l i t y constraints o u t l i n e d i n Section
`2.5 would also apply.
`
`( i i ) P u l l i n g away from a stop l i n e .
`T y p i c a l l y
`t h i s occurs a t signalled i n t e r s e c t i o n s but t h e case
`where d r i v e r s leave the f r o n t o f a slow moving queue
`on passing a t r a f f i c i n c i d e n t i s s i m i l a r .
`Once again
`t h e capacity i s limited, t y p i c a l l y t o about 1800 veh-
`i c l e s per hour per lane, by a combination o f t h e d r i v e r s
`r e a c t i o n time and h i s wish t o increase t h e gap between
`h i s vehicle and t h a t i n f r o n t as the t r a f f i c stream
`speeds up.
`A reduction i n headway o f 0.5 second
`f o r a l l vehicles i n t h e stream would increase capacity
`by about 25 per cent, t o about 2250 vehicles per hour
`per lane.
`This headway reduction i s o f t h e same
`order as the d r i v e r s r e a c t i o n time;
`i f the reaction
`time o f t h e system were n e g l i g i b l e t h i s b e n e f i t need
`n o t be accompanied by an increase i n accident r i s k .
`
`These examples i l l u s t r a t e t h a t PRO-NET systems could
`provide a major increase i n road capacity a t t h e expense
`o f the i n t r o d u c t i o n o f systems o f considerable com-
`There are many
`p l e x i t y i n t o the d r i v i n g process.
`p r a c t i c a l problems t o be solved before such systems
`could be considered a r e a l i s t i c option.
`
`2.7
`Longitudinal Control
`Longitudinal control
`can be viewed as a s i m p l i f i e d version o f PRO-NET.
`Vehicles are f i t t e d w i t h sensors t o measure t h e separa-
`The outputs from
`t i o n from t h e vehicle i n f r o n t .
`these sensors are processed and t h e outputs are l i n k e d
`t o t h e vehicle brake and accelerator c o n t r o l s so t h a t
`as d r i v e r s move towards t h e vehicle i n f r o n t t h e con-
`t r o l s are overridden t o allow i t t o operate w i t h a
`Systems o f t h i s type have
`separation o f a few cm.
`been demonstrated by PROMETHEUS partners, i n p a r t i c u l a r
`by Volkswagen.
`
`The p o t e n t i a l increase i n road capacity by close f o l l o w -
`i n g allowed by these l o n g i t u d i n a l control systems
`For example i f cars operated w i t h i n a
`i s large.
`6m s l o t i n a uniform stream o f t r a f f i c a t 100 km/hour
`t h e t h e o r e t i c a l capacity i s over 16,000 vehicles per
`However t h e technical problems are
`hour per lane.
`Drivers might be uneasy t r a v e l l i n g a t
`formidable.
`high speeds w i t h minimal separation from t h e vehicle
`i n f r o n t and there would s t i l l be considerable problems
`i n developing an i n t r o d u c t i o n strategy, p a r t i c u l a r l y
`i f reserved lanes were necessary, as seems l i k e l y .
`
`These types o f system pose major psychological,
`environmental and technical problems.
`Nevertheless
`t h e b e n e f i t s o f the approach may j u s t i f y s i g n i f i c a n t
`It might be impossible
`e f f o r t t o overcome them.
`t o achieve the f u l l 16,000 vehicles per hour per lane
`capacity but a p r a c t i c a l system could perhaps manage
`6,000 by using platoons o f about 100 vehicles, w i t h
`s i g n i f i c a n t gaps between them t o allow f o r vehicles
`j o i n i n g a platoon from t h e r e a r o r f o r a platoon
`s p l i t t i n g t o allow vehicles t o e x i t a t a junction.
`It would be d i f f i c u l t t o operate these platoons i n
`one p o s s i b i l i t y i s a lightweight
`normal mixed t r a f f i c ;
`road w i t h dual s i n g l e lane carriageways f o r cars only.
`This could be b u i l t a t t h e side o f o r elevated above
`e x i s t i n g road and r a i l l i n k s .
`Such a lightweight
`road might o f f e r t h e capacity o f a three lane motorway
`a t a f r a c t i o n o f t h e cost and would f r e e the conven-
`t i o n a l network f o r heavy t r a f f i c .
`Accident r a t e s
`These roads could be
`might be lower f o r normal roads.
`b u i l t i n r u r a l o r urban areas.
`The technical problems
`are d i f f i c u l t , but t h e p o t e n t i a l gains are enormous.
`
`This high capacity road system could only be adopted
`if technology made t h e necessary high r e l i a b i l i t y
`The reserved lane option i s
`systems available.
`a t t r a c t i v e because these roads could operate apart
`from t h e normal t r a f f i c congestion.
`The enhanced
`l e v e l o f service available on these roads would
`allow t h e option o f operating platoons a t moderate
`speeds, possibly i n the 100 t o 120 km/hour range,
`w h i l e s t i l l achieving acceptable journey times.
`This might be desirable t o minimise energy consumption
`i n f u t u r e decades.
`
`i s t h e t h i r d p a r t
`2.8
`PRO-ROAD
`PRO-ROAD
`o f t h e i n d u s t r i a l research programme and i s concerned
`w i t h systems which depend on comnunication between
`t h e vehicle and roadside equipment.
`T y p i c a l l y
`these are information systems and dynamic r o u t e
`guidance systems.
`Three o f t h e thematic p r o j e c t s
`are p r i m a r i l y concerned w i t h t h i s area.
`They are:
`- Information Processing and DATA a c q u i s i t i o n
`( i n c l u d i n g d i g i t a l mapping);
`- PRO-ROAD System Engineering and Standard-
`i s a t i o n and;
`- On-board elements.
`I n e v i t a b l y some aspects o f these thematic p r o j e c t s
`overlap i n t o the areas covered by PRO-CAR and PRO-NET.
`For example t h e l a s t o f these p r o j e c t s i s concerned
`w i t h the i n t e g r a t i o n o f the systems and equipment
`needed f o r t h e f u l l range o f PROMETHEUS functions.
`It includes work on the architecture and s t r u c t u r e
`o f the system needed t o provide dynamic r o u t e
`However some o f t h e information systems
`guidance.
`being developed w i t h i n PRO-CAR would need t o interface
`w i t h t h i s system.
`
`i n t h a t when
`PRO-ROAD was unusual w i t h i n PROMETHEUS
`i t began there was already an a c t i v e programme i n
`progress elsewhere i n Europe.
`The ALI-SCOUT i n f r a -
`r e d r o u t e guidance system was being developed w i t h i n
`West Germany (2) and plans were being advanced f o r
`A t t h e same time
`a major demonstration i n Berlin.
`t h e prospects f o r providing a dynamic r o u t e guidance
`system, known as AUTOGUIDE, were being assessed
`i n the UK (3). Both o f these systems had consider-
`able i m p l i c a t i o n f o r vehicle manufacturers and i t
`was natural t o include these systems, and r e l a t e d
`developments such as the CARMINAT system being dev-
`Research
`eloped i n France, w i t h i n PROMETHEUS.
`i n t o t h e t r a f f i c impacts o f these systems was
`established