Origin-destination matrix estimation for the active traffic management project

The Highways Agency (HA) is developing the concept of Active Traffic Management (ATM) schemes which will coordinate operational regimes such as controlled use of the hard shoulder as a running lane, variable speed limits and ramp metering. The pilot ATM scheme is planned to be implemented on the eastern section of the M42 between Junctions 3a and 7 by 2006. To ensure the success of all these measures, and to enable the network to be managed safely and effectively, knowledge of the behaviour of the traffic on the network is vital. Origin-destination (OD) demand matrices are at the core of this information, but direct monitoring of trips is at present expensive and unreliable. The principal data sources available to traffic management systems remain inductive loops, which will provide dense coverage on the ATM section with 100m spacing, as compared with 500m spacing on the M25. The new and enhanced methods of dynamic origin-destination matrix estimation (ODME) developed in this project are designed to exploit this and to. support the sophisticated real-time control systems on the section. This paper describes the methods and results of the project conducted in three phases.