Taipei, June 6 (CNA) A ban on changing lanes in Hsuehshan Tunnel, which is part of Freeway No. 5 that links Taipei and Yilan County in northern Taiwan, will remain in place, the Directorate-General of Highways (DGH) said on Tuesday.
The DGH said it assessed a proposal that lane changing would help to ease congestion within the 12.9-kilometer tunnel, but concluded that the measure is unfeasible because changing lanes increases the danger of traffic accidents.
Traffic jams on the freeway are particularly severe during holidays when the number of vehicles passing through the tunnel increases, prompting the DGH to reevaluate the possibility of permitting lane changes in the tunnel. However, the review found that changing lanes would likely increase the incidence of accidents and so the ban will remain in place.
Releasing its study on the issue, the DGH said increasing the number of vehicles in the middle to final sections of the tunnel does not obviously improve traffic flow but does increase the risks of an accident.
If lane changing was permitted, the chance of a collision between two vehicles from two lanes, bumping into the vehicle in front or a single-vehicle accident would increase, said the DGH.
As the tunnel does not have a shoulder lane, any accident would be more likely to force the closure of both lanes -- unlike the current situation where only one lane is closed in the event of minor accidents, it added.
It also cited data from 2014 to 2016, saying the number of road accidents outside the tunnel was 2.2 times that inside the tunnel on the highway's northbound lane and 1.2 times on the southbound lane, strongly suggesting that a strict ban on lane changing inside the tunnel increases road safety.
In the event of a fire inside the tunnel, it also would likely be more of a challenge for fire engines and ambulances to reach the site, said the DGH.
