Dynamic, affordable, liveable and attractive urban regions will never be free of congestion. Road transport policies, however, should seek to manage congestion on a cost-effective basis with the aim of reducing the burdenthat excessive congestion imposes upon travellers and urban dwellers throughout the urban road network. Effective land use planning and appropriatelevels of public transport service are essential for delivering high quality access in congested urban areas. Integrated land use and transport planning and coordinated transport development involving all transport modes,including appropriate levels of public transport, are fundamentally important to the high quality access needed in large urban areas. Road users require reliable door-to-door trips that are free of stress. Road users generally accept a degree of road congestion but attach a high value to the reliability and predictability of road travel conditions. Reliability needs to be given greater weight in assessing options and prioritising congestion mitigation measures. Targeting journey time variability and the most extreme congestion incidents can deliver rapid, tangible and cost-effective improvements. Unreliable and extremely variable journey times impose the greatest inconvenience on road users. An increase in the reliability and predictability of travel times can rapidly reduce the cost associated with excessive congestion levels. The age of unmanaged access to highly-trafficked urban roads is coming to an end. Most traditional congestion relief measures either free up existing capacity or deliver new road capacity, which is likely to be rapidly swamped with previously suppressed and new demand,at least in economically dynamic cities. In future, demand for use of highly trafficked roads will need to be managed. Demand management strategiesshould take full account of how residents and roadway users wish to see their community develop as well as their longer term mobility preferences. Transport authorities will inevitably need to employ a combination of access, parking and road pricing measures to lock in the benefits from operational and infrastructure measures aimed at mitigating traffic congestion. By comparison with non-road infrastructure managers, road administrations generally have much less of a role - if they are assigned any role at all -in managing overall levels of demand. Often little consideration is givento the question of whether overall demand for use of the roadway system should be managed at all. For the covering abstract see ITRD E139491.
Abstract