The article describes some of the changes in traffic flow and accidents on the Ml in Northamptonshire associated with the motorway reconstruction work and in particular a change in crossover design. Changes in traffic flow on adjacent routes are also considered. At first a single lane crossover system involving a relatively sharp bend and having an advisory maximum speed of 30 mph was used. After a hard shoulder had been reconstructed to carry traffic a revised design of crossover taking two lanes of traffic across the central reservation together and having a smoother alignment with a design speed of 50 mph was introduced in 1982. It is found that the new crossover design has reduced accidents during contraflow and has also reduced transfer of traffic to other less direct routes.
Abstract