CHICAGO (CBS) —  Six years after the city installed the protected bike lanes along Dearborn Street, now they are being replaced,

Construction on the four-week project is underway. The city claims replacing old bike lanes with new ones on Dearborn is to increase bike safety; but some cyclists are not so sure, CBS 2’s Derrick Blakley reports.

“I don’t think cars are going to come into those lanes anyway,” said Ben Reasner, a bicyclist. “I don’t feel threatened. I think it’s just more concrete in the city, actually.”

The current Dearborn bike lanes use plastic poles, known as bollards, to protect cyclers from car traffic. The new lanes, the one ones already installed on Milwaukee, use a wide, flat concrete barrier. Cycling advocates insist it is safer.

“These concrete curbs make it much more difficult for vehicles to be able to enter and obstruct the bike lane,” said Jim Merrell of Active Transportation Alliance, a bicycling advocacy and safety group.

The Dearborn bike lane upgrade from Polk Street to Kinzie is among five bike lane projects costing almost $1.2 million.

“That’s really going to shift people out of their car trips and really help us tackle the congestion in the city, we know is a big challenge for so many,” said Merrell.

The city said the money comes from a federal grant, not local taxes.

Note:  This story has been corrected. The City Department of Transportation now says the Dearborn Street bike barrier is among five bike lane projects totalling $1.2 million.  Based on initial information from CDOT, CBS previously reported the Dearborn project alone totalled $1.2 million.