An optical method for automated roadside detection and counting of vehicle occupants

Abstract

The monitoring and control of traffic volume is becoming a constant social, economic, and environmental pressure in the UK and elsewhere, because of landmass and current infrastructure strain under a swelling and increasingly mobile population. The viability of high-occupancy vehicle (HOV) lanes for easing traffic congestion, and hence maximising traffic flow, has been proven in countries worldwide. The USA, Australia, and Canada have had HOV installations for some time, controlling the flux of traffic into their most densely populated areas. Experience in these cases has dictated that it is enforcement which is crucial to the successful implementation of such a traffic policy. To date, all enforcement has been manual, i.e. a police officer counting the occupants in a vehicle as it passes by. Studies have concluded that manual enforcement is typically only 65 per cent accurate and, considering the pressures which one individual is put under in these circumstances, this statistic is not surprising. Lighting and environmental conditions, skin tone, and location of the occupants and the alertness of the officer are all variables affecting the accuracy of manually collected data. Hence there is the need for an autonomous detection system to count the occupancy within a vehicle. This could provide the basis of an enforcement or congestion strategy.