Access Control using ramp metering techniques was introduced at Junction 10 of M6 in May 1986. This paper details its success in reducing delays and saving user costs. The Access Control Scheme at Junction 10 of M6, a form of ramp metering, was introduced in May 1986. Traffic on the Southbound entry slip road is held at traffic signals at times when its entry to the main carriageway would lead to a breakdown of smooth flow or would worsen the congestion on the motorway. Both of these conditions are associated with a reduction in the effective motorway capacity. This paper briefly outlines the physical layout of the scheme and the mode of the operation, and comments on driver behaviour and safety. It then discusses the impact of the scheme on traffic flows both on the motorway and on the all-purpose network. The capacity benefits and delay savings to motorway traffic are then discussed. The saving in delays in the first year of the operation is estimated to have been worth 100,000 pounds.
Abstract