Minneapolis has slapped new restrictions on idling motor vehicles and prohibited booting motor vehicles except when towing isn't feasible.

The City Council approved both those items unanimously Friday, but it split on several amendments before approving a voluntary registration plan for sidewalk assemblies during the Republican National Convention.

The idling rules cover both gas and diesel vehicles, going beyond restrictions imposed on diesel-powered commercial vehicles earlier this year.

Council Member Sandra Colvin Roy, who initiated the restrictions, said they're aimed at improving air quality in a city that racked up 178 moderately unhealthy air-quality days last year, according to state measurements.

In general, vehicles can't idle for more than three minutes in a one-hour period. But there are a number of exceptions.

In weather below zero degrees or more than 90 degrees, vehicles could be run for up to 15 minutes in an hour for the comfort and safety of the occupants. And the temperature restriction doesn't apply to vehicles that carry paying customers. Emergency and other vehicles that need to idle to power auxiliary systems such as computers or lifts would also be exempt. Auxiliary power units could also be run. Idling also is OK forvehicles stopped by congestion or idling for garage repairs.

Colvin Roy said the city will emphasize education more than enforcement, but said provision will be made for people to report violations on the city's 311 information line. Administrative citations would be issued first, and criminal penalties could occur only for repeat violations in a two-year period.

The council acted on the vehicle immobilization practice known as booting after its regulatory staff urged ending the practice. That came three years after the council adopted new restrictions on the practice, used to penalize those who park in private lots, but staff reported repeated violations of those limits by those applying the boots. Numerous complaints about booting also were reported. "This is not something that is working," said Council Member Gary Schiff, who proposed the ban.

Force Management, a booting firm that the city reported generates more complaints than any other, argued that complaints are prompted by the city's requirement that a complaint procedure be given to customers. It said this holds booters to a higher standard than towing companies.

Booting will be permitted in private lots only where the city agrees that tight quarters make towing unfeasible. The fee that can be charged the driver to remove the boot is cut from $103 to $50.

The council also approved a resolution on an 11-2 vote that encourages protesters using public grounds to register their assembly with the city. There's no penalty for not doing so, but registered groups planning a gathering of more than 50 people that keeps people from using sidewalks and crosswalks will gain priority for a space over unregistered groups. The new policy is limited to the 15-day period from Aug. 25 to Sept. 8 at the initiative of Council Member Elizabeth Glidden.

Schiff and Cam Gordon cast the only votes against the new plan, which was opposed by the American Civil Liberties Union. It follows months of discussion.

Steve Brandt • 612-673-4438