|The aim of this paper was to examine if Norwegian speed limits on freeways could be more
efficient from a social economic standpoint. We examined the relationship between regulations
in speed limits and actual speed held by vehicles on Norwegian freeways, as well as looking at
how this regulation changes the magnitude of traffic. With these estimations of relationship, we
sought to estimate actual benefits and costs of a change in speed limit from 110 km/h to 120
km/h by analyzing the change from 100 km/h to 110 km/h and apply this to a potential change
from 110 km/h to 120 km/h. There are few studies on this topic in Norway and seeing, as this
is a very hot topic politically in Norway today, we found this study to be of interest. With hourly
counting data for two Norwegian freeways, we analyzed the effect of a change in the speed
limit from 100 km/h to 110 km/h on actual speed change and change in traffic magnitude. With
these results, we wanted to see if it would be economically efficient to increase the speed limit
further from 110 km/h to 120/km on Norwegian freeways.
Based on a sharp regression discontinuity design (RDD) analysis of the increased speed limit
on freeways E39 Skoger and E6 Kløfta Sør we found that only smaller vehicles benefits from
the increase in speed limit, when it comes to time saving. Other vehicles are observed to be
given no time savings, as these vehicles are restricted in Norwegian law to drive no faster than
For smaller vehicles, an increase in the speed limit from 100 km/h to 110 km/h resulted in an
increase in observed speed between 2.59 km/h and 2.93 km/h. With an increased maximum
speed limit from 110 km/h to 120 km/h we get an increase in the average speed held by drivers
from 110 km/h to 113 km/h in the left lane and from 101 km/h to 104 km/h in the right lane.
We saw no direct effect on the traffic magnitude on the roads of the higher speed limit, but we
observe an increasing trend. Utilizing our estimates for actual speed increase and traffic
magnitude from the impact of an increase of maximum speed limit to 110 km/h, we try to
evaluate the economic impact of a further increase to 120 km/h.
To determine the economic effect of a further increase in the speed limit, we used a cost-benefit
analysis and sensitivity analysis on actual speed increase and the effect of using our estimated
value of time. We found that per year, people save on average 232 NOK with a speed increase
of 3 km/h.
With a cost-benefit analysis of a further increase in the maximum speed limit from 110 km/h to
120 km/h on existing freeways, running sensitivity analysis on actual speed increase, with no
change in observed traffic magnitude and change in time value, we estimate that the total social
economic effect of this shift varies between 280 MNOK and 1694 MNOK.