The potential of high-occupancy vehicle (HOV) lanes to reduce congestion by encouraging car pooling is discussed. In the UK the commonest HOV lane is the bus lane. The expansion of HOV lanes in the USA is described but not all of these have been successful or conversion to toll roads has been proposed. HOV lanes do not necessarily reduce emissions and may increase accident rates on motorways. The HOV lane in Leeds, UK led to the formation of car pools, reduced emissions and shorter journey times and is considered successful. Compulsory lorry lanes to improve traffic flow, reduce accident rates, respond to public pressure and reduce pavement wear are described. A major safety problem is that there may not be enough gaps between the lorries for other vehicles to exit the highway and the increasing speed of other vehicles may increase the potential for accidents. The most basic category of lorry lane is the crawler lane provided on hills. Another system is to provide an overtaking lane for passenger vehicles, or to prohibit lorries from certain lanes on the motorway. Problems at motorway junctions are described, including whether to place lorry lanes in the centre of motorways with three lanes. Short crawler lanes may be cost-effective but total segregation of lorries is not.
Abstract