Trevor has more than 18 years' experience as an independent consultant specialising in road-user charging systems. Trevor has worked on many major RUC schemes, including in the UK the London Congestion Charge, low-emission/clean air zones in London and four other cities, as well as the Dart Charge and Tyne Tunnel multi-lane free-flow (MLFF) systems. In Ireland, Trevor has worked on the M50 and Dublin Tunnel toll systems. In Denmark, Trevor has worked on the distance-based truck toll, the Frederikssund Bridge MLFF system, and the Storeabælt Bridge toll. In the Netherlands, Trevor is presently working on the distance-based truck toll (Vrachwagenheffing), and the Blankenburgverbinding MLFF toll.