A simplified model has been worked out to analyze the benefits from an urban motorway by the reduction in accidents, travel time and fuel consumption. These benefits were higher than expected, because of a higher level of included traffic. Also there were relatively more savings from higher accident reduction and less from fuel savings. Largest component in total benefits remained value of travel time saved. A minimum travel time ratio was introduced, depending on type of road, type of car, congestion, from which the actual travel time can be derived. A formula is given to calculate travel time benefits on motorways and trunk routes. Good agreement is established. A formula is also given for the calculation of the benefits from the reduction in accidents for diverted and generated traffic. Fuel consumption savings are not estimated separately, since they amounts to 1% of travel time savings or 8% of accident reduction benefits.
Abstract