IMPACT OF TRAFFIC REGULATION IMPROVEMENT ON ENERGY-CONSUMPTION AND POLLUTANT EMISSIONS FROM PASSENGER CARS

An assessment method has been developed and used in one case of improv ment of the traffic regulation systems: optimization and extension of the centralized management system in Amiens. The objective was to meas ure the real impact according to trip duration, fuel consumption and p ollutant emissions, using two vehicles equipped with instruments, driv en on predefined routes, at various times, before and after the puttin g into operation new equipment, and at a year interval. The study conc erning the town of Amiens yielded results at a methodological level, i n particular for fuel consumption measurements, and significant gains: significant reductions in total durations, stop numbers and stop dura tions are observed on some routes, systematically leading to consumpti on reductions. Consumptions vary considerably with traffic conditions (in a ratio of 1-2). Time is the preponderant factor in the variation of the analyzed variables. A microscopic analysis between intersection s is used to identify with accuracy 'sensible spots', and the effects of the regulation system on a limited number of sections. An assessmen t study over 4 daily hours from traffic data yielded the following red uctions: 7% on travel duration, 23% on stop duration, acid 3.8% on con sumption, without an increase of speed. These significant gains show t he advantage of this operation, at least in the short term. Gains main ly relate to off-peak hours, and concern a limited number of sections or crossroads. The evening peak hour is most inportant in the search f or other increases, as it corresponds to over a third of travel durati ons and fuel consumptions (more than 1 litre/100 km as compared to ave rage values). Simultaneously, significant reductions in carbon monoxid e and hydrocarbon emissions are expected, as well as an increase in ni trogen oxide emissions, confirmed by measurements performed on a chass is dynamometer for two vehicles, and driving cycles derived from kinem atics recorded in Amiens. The method and the analysis are described, u sing the case of Amiens.