Mobility in the post-corona era. Possible effects of motorway extensions on public costs and benefits

For a period of approximately two years, Dutch society was subjected to measures by which the government tried to limit the spread of the SARS-CoV-2 virus. These measures had a major impact on the way people travel and particularly on the number of traffic jams on motorways. One of the issues this raises is whether these behavioural changes will become structural or partly structural. The main research question of this study is therefore: Is there any indication that planned motorway expansions will become less socially profitable because mobility behaviour does not return to the pre-corona situation, which means that congestion remains lower for a long period/permanently?

Data analysis on two specific sections where road extensions are planned in the context of the Multiannual Programme for Infrastructure, Space and Transport (MIRT) confirms the image that there was significantly less congestion on roads during the corona measures. The data analysis also shows that the format of the rush hour differed from the pre-corona situation. During the corona measures, the peak rush hour was relatively more concentrated, i.e. a larger proportion of rush hour traffic was concentrated around a shorter period of time.

This more concentrated rush hour on these relatively busy routes in 2019 can be explained by ‘evasive action’: people sought the outer limits of the rush hour, by leaving earlier or later, and thus spent less time in traffic jams. On the routes analysed, there was so much traffic in 2019 that the congestion caused the rush hour to expand. In that situation, there was a ‘latent demand’ for road capacity in the classic rush hours. When the lockdowns reduced the congestion, the rush hour became concentrated into a shorter period as motorists opted for the classic rush hour times and there was no longer any need to take evasive action.