The state Transportation Department is asking for $40 million to build an afternoon contraflow lane on the H-1 Freeway west-bound.

It is also seeking $100 million to add an east-bound lane starting at the Middle Street merge, one of the worst bottlenecks on the island.

The contraflow project would add a lane with a concrete barriers from the Radford Drive overpass to the Waiawa Interchange.

Construction would start in January 2010, and wrap up within 12 to 18 months.

The project is part of a plan to ease traffic congestion, especially for those living in Central and Leeward O'ahu, said Brennon Morioka, state DOT director.

The afternoon contraflow lane, which would extend for a 6.2-mile stretch, is expected to save west-bound commuters about 5 to 10 minutes, the DOT said.

The extra lane starting at Middle Street merge is expected to save commuters up to 20 minutes. Construction on the project is slated to start in early 2011.

The capital improvements project were announced at a news conference today with the governor, lawmakers and transportation officials.