This paper presents a quantitative study of the effects of roadside carbon monoxide (CO) levels under demand-responsive traffic control policies. Moving-car observer surveys were conducted to assess traffic control network performance with: (1) fixed-time settings; (2) SCOOT constrained to run according to an updated fixed-time plan; and (3) with full SCOOT operation. Kerbside levels of CO and traffic characteristics data were collected continually. The region chosen for the study was Queens Road in the Beeston suburb of the English city of Nottingham. Roadside pollution monitors were placed at three locations along the road. Pneumatic tube detectors were placed at the entry lane at each end, to measure flows along the road. The paper presents the survey methodolgy, data acquisition procedures, and the results of the statistical analyses. Summary tables are given for CO levels measured at the roadside at two junctions and at a mid-link site. On the whole, the updating of the old fixed-time plan led to significant benefits, which were maintained after a month of SCOOT operation, which led to reduced peak traffic flow levels compared. A study of the ageing of traffic signal plans between 1989 and 1995 showed potential benefits of 8% for a SCOOT operation continually responding to changes in traffic demand.
Samenvatting