Signs on both sides of the entrance ramp leading from 31st Street and Stevens Avenue to southbound I-35W tell motorists, "Do Not Enter." Yet dozens of vehicles an hour are blowing right by them to use the ramp reserved exclusively for buses and emergency vehicles.

The same thing is happening on the ramp from northbound I-35W to 31st and Lake Streets, even though the exit is marked with signs and the words "Buses Only" are painted on the pavement.

The Minnesota Department of Transportation is asking motorists to knock it off. "We realize it is inconvenient," said MnDOT spokesman David Aeikens. "We can't close the road. We need buses to get through. We are hoping people will do the right thing and not drive illegally on the ramps."

MnDOT closed the ramps to general traffic in June as part of the massive $239 million downtown-to-Crosstown reconstruction project. The agency left them open for buses to provide a way around congestion and a quicker route to downtown Minneapolis via Park and Portland avenues. The goal was to get more people to take transit and reduce the number of vehicles moving through the area where the freeway has been squeezed to two or three lanes instead of the normal five in each direction.

"We can move more people on a bus," Aeikens said.

But with so many drivers using the exit and entrance ramps, some buses have had to wait to get on them, negating the transit advantage they are supposed to have.

"It does impede our service," said David Hanson, Metro Transit's assistant director of field operations. "This is a flagrant disregard for traffic control devices."

Besides being against the law, motorists using the ramp to southbound I-35W are putting themselves in harm's way, Aeikens said. The passage is too narrow to allow drivers to safely merge into traffic, Aeikens said.

The current configuration directs southbound drivers to Nicollet Avenue and down to 46th Street where they can access the freeway. Northbound drivers can get off at 46th Street or at 3rd Street in downtown Minneapolis.

At the outset, MnDOT was paying the State Patrol $100 an hour to guard the ramps, but it's not an option to have them there 24 hours a day, Aeikens said.

"They should not have to be there; they have better things to do," Aeikens said. "We realize having to go to another exit adds extra time. We'd appreciate if people would use the detours."

MnDOT made a similar plea last summer when it shifted traffic to one side of the Lowry Hill Tunnel and banned trucks and oversized vehicles from passing through. Several did not heed the plea and damaged lights inside the tunnel when the "road was open, but it was not open," Aeikens said.

It's like that now: The 35W ramps are open, but they are not open, he said.

The State Patrol has issued tickets to drivers illegally using the 31st Street ramps, but it was not immediately clear how many, said Lt. Tiffani Nielson. Miscreant motorists who get caught face a $145 fine, which would rise to $300 if the trooper marks on the citation that the violation was in a construction zone. Court costs could be tacked on as well.

"There are lots of signs," Aeikens said. "We need people to follow law."