DENVER -- An estimated 2.1-million people ride bicycles in Colorado, sharing the roads with countless motorists.

"It gets a little scary," said Cheree Lueck, who rides her bike home from work on Saturdays. "I've never been hit, but I've been close to being hit."

Lueck said the close calls make her want to ride on the sidewalks, but that's not allowed in Denver.

On Monday, Gov. Bill Ritter signed a bill aimed at making roads safer for motorists and bicyclists.

The measure (Senate Bill 148) requires that drivers give cyclists at least 3 feet of space when passing or risk a $110 ticket.

The executive director of Bicycle Colorado, Dan Grunig, told 7NEWS that the buffer will give bicyclists flexibility to maneuver around road debris and to deal with other factors, like wind.

"Even wind from a passing vehicle can cause bicyclists to change their course a bit," Grunig said. "So providing that safe distance helps insure that if there's a rock or a pothole in the bikers way, that they're not in the way of a car too."

The new law also deals with a form of road rage.

Anyone who throws an object at a cyclist could be charged with a class 2 misdemeanor. That carries a fine of between $250 and $1,000 and a possible sentence of three to 12 months in jail.

"That type of behavior is never alright," Grunig said. "It could potentially cause a crash."

The new law also makes it a class one petty offense for anyone to throw an object at or against any vehicle.

The bill was sponsored by a bipartisan pair of avid cyclists -- Republican Sen. Greg Brophy of Wray and Democratic Rep. Mike Merrifield of Colorado Springs.

Ritter says the new law, which takes effect Aug. 5, will "enhance safety for everyone." He signed the bill along with six others Monday in Colorado Springs.

"One of the great things about Colorado is that so many people love to bike," Ritter said noting that he, Rep. Merrifield and Sen. Brophy all are avid cyclists. "But it also means that cyclists and motorists alike must take extra precautions so that we can share the road safely."