함마대로는 1995년부터 4차선 확장 공사를 실시하였으나, 공사비 예산 문제로 2007년에 와서야 4차선으로 확장 개통되었다.
Hammadaero Road had been expanded to four lanes since 1995, but due to budget issues for the construction cost, it was expanded and opened as the road with four lanes finally in 2007.