Communication between people on the Héðinfjarðar-tunnel: Traffic and comparison with traffic forecast

Abstract

A traffic forecast was made prior to the opening of the Héðinsfjörður-tunnels between the towns Siglufjörður and Ólafsfjörður in 2010. The forecast was based on a traffic survey where all traffic in the northern Tröllaskagi peninsula was stopped on a total four days in summer and winter. The forecast did not only involve total traffic but also predicted changes in interactions between towns after the tunnels. The same kind of traffic survey after the tunnels showed that the gravity model in it simplest form gave a good estimate of the total tunnel traffic. It did, however, not give good results regarding traffic between different towns. In that case the scaled gravity model gave a good estimate of the proportions of each leg of the total traffic. The scaling was based on traditions of communication continuing after the opening of the tunnels. For instance, there was a greater tradition for communcation between Siglufjörður and Ólafsfjörður before the tunnels than predicted by the gravity model. The scaled gravity model correctly assumed that such traditions would continue after the tunnels.