BYTRANS: Effects and consequences of capacity reduction in the Bryn tunnel Documentation report

The report analyses adaptions to, and effects and consequences of a capacity reduction from four to two lanes in the Bryn-tunnel, and of the tunnel regaining full capacity a year later. Road users (commuters, delivery transport and taxi) adapted in ways resulting in significant reduced traffic in the tunnel and this part of the road system. They adapted by choosing other routes, other means of transport, other trip-timing and more frequent use of home office. Average speeds were anyhow significantly reduced in rush hours. When the tunnel regained full capacity, traffic increased, but to lower levels than in the before-situation. We found mainly minor changes in traffic volumes and speeds in other parts of the road system. The delays and adaptions caused disadvantages to all types of users, but not large negative consequences. A main finding is hence that halving the capacity of one of Norway's heaviest traffic links did not cause crisis or chaos.