Shadow tolling - a challenge to traditional traffic counting techniques

In 1995, the first contracts were let by the UK government which privatised parts of the UK road network. Private companies are for the first time responsible for the design, build, finance and operation (DBFO) of roads used by the British public. In an attempt to match the income to the DBFO companies to the use made of the roads, a significant proportion of these payments is directly based on the total traffic flow over the scheme. The importance of this "shadow tolling" revenue to the DBFO company is self evident, and that the payments made are fair. In preparing for shadow tolling, the UK Highways Agency consulted with industry in arriving at the need for highly accurate traffic counters to monitor road usage over entire schemes for the next 30 years. This paper addresses the challenge faced by the industry, and the solutions developed to provide tolling systems with full compliance, well ahead of the required schedule.