A model which evaluates the various measures of service for each of the hours of operation of a highway in a year is presented. It performs a simple economic evaluation in which the benefits of upgrading a highway are summed for an entire year and compared to the annualised additional costs of construction and maintenance, providing decision makers with the tools required to decide whether the benefits of upgrading justify the required construction costs. Each hour of the year is evaluated on an individual basis by estimating its performance in terms of travel time, driver frustration, and safety, for the predicted or observed traffic volume for that hour. This performance is translated into corresponding costs, which are summed to obtain the total user cost for the year. Since hourly directional traffic volumes are generally available to highway departments which use automated data collection, the model allows for separate treatment of traffic by direction, so that directional peak volumes are reflected appropriately. It also allows for consideration of weather effects on capacity, so that the actual interaction of specific hourly supply and demand volumes are reflected. The use of the model is demonstrated through evaluation of the possible upgrading of a 2-lane, 2-way rural highway in Ontario to 4-lane standards.(a) for the covering abstract of the proceedings see IRRD 274491.
Abstract