An overpass constructed, at a cost of 650 million yuan ($9.74 million), to ease traffic jams was found to have worsened traffic congestion in Zhengzhou, capital of Henan province.

The overpass, the biggest of its kind in Zhengzhou, was opened on June 27, but has done little to solve traffic congestion issues.

"Instead, it has exacerbated traffic congestion. It takes me at least half an hour to drive 1 kilometer since the overpass was opened," a resident surnamed Zhang said.

The overpass was connected to Zhongzhou Road, which is the main road leading to the CBD in Zhengdong New District.

Zhengzhou's urban planning department said it has summoned other departments to discover why the overpass has been ineffective, and vowed to take measures to improve the situation before Oct 10.

Local media quoted drivers as saying that the problems were probably caused by a sudden decrease in the number of lanes, from nine to four.