A practical method for balancing modal provision on congested urban corridors

Many urban corridors are confined by historical constraints that limit the space available for each mode, causing congestion and crowding. Planners and engineers have often sought to optimise the space available for general traffic and more recently buses because the modelling tools and data are readily available to quantify the improvements possible. The lack of these tools and data for pedestrians and cyclists has led to the historical shift of urban centres from pedestrian dominated to traffic dominated. This paper presents a fresh approach to the problem by assessing journey time delay on the basis of unit time rather than unit distance, which compensates for the disparity in average speed between modes. The principle uncertainties result from a lack of data on the speed of cyclists in different conditions, for which further study is recommended, and the incorporation of freight into the assessment. The method is intended for guidance and is not prescriptive; issues such as road safety, DDA compliance, streetscape, etc, must also be considered by the planner/engineer. However, a simple worked example of a hypothetical average London street illustrates the key benefit of this new method in providing guidance on achieving the best balance between general traffic and bus lanes, cycle paths and footways, based on the available corridor width and number of people moved by mode. Further application in the provision of crossings, street furniture, and cycle paths is discussed. This practical method is recommended for use by planners and engineers to provide useful guidance at an early stage in the design process.