SOUTHAMPTON SITE

The Southampton Network

Southampton has a regional airport near its northern boundary with services to many European countries. The M27 motorway passes on an east/west axis to the north of Southampton diverting through traffic away from the city. A short stretch of motorway (M271) links the M27 with the western area of the city including the western docks. Southampton Central railway station is served by three fast trains per hour to and from London during much of the working day with regular train services to many other towns and cities in England, Scotland and Wales. There are also long distance coach services into Southampton, including a regular service to and from London.

The Bassett Avenue (A33) test site is a four lane un-segregated arterial linking the North of Southampton to the M3 motorway. It is effectively a dual carriageway, there being no physical segregation of the North and South traffic flows. Twelve single inductive loop detectors (2m x 1.5m) have been installed in the two Southbound lanes and eleven in the North bound outside lane at approximately 100 metre intervals between the Chilworth and Winchester Road roundabouts (a distance of 1150m).

The Winchester Road test site joins Bassett Avenue at the Winchester Road roundabout. Eleven single inductive loop detectors have been fitted in the North and Southbound carriageways along its 898m length to Hill Lane roundabout. A further series of eleven loops being used to control traffic signals also form part of the test site between Hill Lane roundabout and Warren Avenue, a distance of 941m.

Both roads have speed limits of 64 km/hr (40 mph) and are heavily congested during peak hours. The traffic using Bassett Avenue and Winchester Road during the morning peak period (07:30 - 09:15) consists of 96% and 93% car length vehicles (3m to 4.9m) and 4% and 7% long vehicles (greater than 4.9m) respectively. Parking by the roadside was permitted along Winchester Road between the Winchester Road and Hill Lane roundabouts whereas parking was prohibited along the entire length of Bassett Avenue.

The single inductive loop detectors used are sampled every 250-ms for their occupancy status. These raw data are transmitted on-line to the ROMANSE Office, where they are then processed and aggregated into time slices of 30-seconds and 5-minutes. Algorithms have been developed to process the occupancy data to provide measurements of flow, percentage occupancy, speed (km/hr), Average Loop Occupancy Time Per Vehicle (ALOTPV) and Average Time Gap Between Vehicles (ATGBV) for the previous time interval (either 30-seconds or 5-minutes). Currently, all Southampton detector data are collected between 06:00 and 22:00 daily and are archived.

CCTV cameras have been installed along the Southampton test site at the Chilworth and Winchester Road roundabouts, at the Hill Lane roundabout and at the Wilton Road junction.

The off-line and on-line tests of the U06 ID algorithm were conducted on the A33 Bassett Avenue and A35 Winchester Road test sites. The on-line Neural network Journey Time estimation ID algorithm was tested on the Southbound inside lane of Bassett Avenue only.