The expressway will cut travel time between Taipei and Yilan County to around 30 minutes.
Su drove a red open roofed Jeep through the 12.9 tunnel (the longest in Asia and the fifth longest underground link in the world) with former premiers, Frank Hsieh, Yu Shyi-kun and Chang Chun-hsiung. The journey took 20 minutes.
They then participated in the formal inauguration ceremony of the "Chiang Wei-shui Expressway" at the Toucheng Control Station in Yilan County.
During the ceremony, Su quipped that the former premiers had "showed confidence in my driving and I gave them no cause for worry."
According to the National Expressway Engineering Bureau of the Ministry of Transportation and Communications, the Taipei-Yilan Expressway began in 1988 with feasibility planning while construction began in January 1990. It eventually cost NT$90.6 billion and the lives of 25 workers and engineers.
The Chiang Wei-shui Expressway, named after a leading activist during Japanese colonial period, has reduced travel time between Taipei and Yilan County firom three hours to 30 minutes.
Speaking at the Toucheng event, Yu said the opening of the expressway was the "third most important event" in Yilan's history, following the opening and development of the Lanyang Plain over 200 years ago and the launching of the Yilan railway.
Yu said the Yilan County government, now under Kuomintang magistrate Lu Kuo-hua, should pay close attention to its urban development plans. The plans are meant to bolster the local transportation network, parking facilities as well as make sure the increased traffic to Yilan County does not have negative impacts on the county's citizens.
Hsieh said the tunnel was a "huge construction project" in which many people made innumerable sacrifices and "some never returned home."
"There were many wrongs and protests, but history will only remember that Taiwan created a miracle," he said.
Quoting Chiang Wei-shui, he said "unity is what is most important" and "unity is really powerful."
In his remarks, Su said Chiang Wei-shui was someone "who fought for Taiwan democracy and culture, and not for his own interest."
"On this day when we inaugurate National Expressway Number Five or the Chiang Wei-shui Expressway, we should cast our vision further and higher," he said, adding "there is only one Taiwan and only if everyone should appreciate it and struggle for it will we have good fortune."
Before entering the tunnel and going to Toucheng, Su and other dignitaries participated in a ceremony to unveil a memorial at the Shiding Service Area to the 25 workers, including 13 Thai foreign laborers, who lost their lives during the construction of the highway.
Thirteen of the workers, including seven from Taiwan and six from Thailand, died in accidents in the Hsuehshan Tunnel.
Relatives of the deceased Taiwan workers were present at the ceremony.
Su, the former premiers and Transportation Minister Kuo Yao-chi participated in the ceremony. There was reading of a memorial statement and the names of those killed in the accidents. White roses were placed in front of the pyramid-shaped black memorial (upon which the workers' names were engraved).
Kuo said the Hsuehshan Tunnel was one of the most difficult construction projects in the world due to the fragile geological conditions and rich underground water deposits. The conditions led to nearly 40 floods, caused many accidents and seriously hindered construction.
Kuo said a major reason the tunnel construction, which is listed in the Encylopedia Britannica as the most difficult engineering project in the world, could be completed was "the selfless sacrifice of these national expressway workers."
"It took 13 years to dig the tunnel and 15 years to complete the project or about a kilometer a year and in this process 13 domestic or Thai workers lost their lives." Kuo said.
Thailand Trade and Economic Office Labour Division Director Supoj Pongsupat accepted a memorial statuette of two hands folded, as if in prayer, on behalf of the Thai workers.
