Taipei, Sept. 15 (CNA) "Crab lanes" designed to protect land crabs migrating from inland areas to the coast to spawn have generated good results, thanks to new measures introduced this year, the Directorate General of Highways (DGH) said Friday.
During the first round of the program between Aug. 6-8, when the spawning activity peaked during a full moon, the roadkill rate dropped from 7.5 percent to 1.5 percent compared with the same period of last year, according to DGH officials.
"It is an impressive sight when you see hundreds of crabs trying to get to the sea at the same time," said Chien Hao-ting, a DGH engineer responsible for the project.
The species gaining the benefit of the crab lanes include Discoplax hirtipes and Sesarmops impressum, Chien said, adding that the agency is partnering this year with National Tsing Hua University and the Kenting National Park Administration to instigate three rounds of the program on a section of highway in Kenting, in southern Taiwan's Pingtung County.
The area involves the 39.5 kilometer-41.5 km mark on Provincial Highway No. 26, which cuts through an area that is the habitat of more than 20 species of land crab, making it the most diverse known habitat in the world for the creatures, according to local crab experts.
But due to the construction of the highway, the crabs are forced to cross the highway to reach the coast to spawn, and are often crushed by passing vehicles.
Traffic controls have been put in place to protect the crabs crossing the highway in recent years, including road closures of the entire highway section for a period of 120 seconds every 10 minutes between 6:30 p.m. and 8:30 p.m. during summer days with a full moon, Chien said.
But the program this year has been so far the most successful, thanks to more careful travel guidance.
During 10-minute access periods allowed for vehicles in every 20-minute period, a DGH vehicle leads the way and keeps all traffic traveling at less than 30 kilometers per hour.
In addition, a more indirect passage around the 39.75 km mark on the highway provides another route for the crabs to reach their spawning grounds, using canvas to prevent the crabs from crossing the road and directing them through sacking into a culvert under the highway.
The crabs tend to climb on objects with rough surface, Chien explained.
Cameras have also been installed at both ends of the culvert to keep a record of the crabs' behavior for better protection measures in the future.
One of the following two rounds of the program took place from Sept. 5-7, with the other slated for Oct. 4-6, according to the agency.
