Houston's streets are slated to become safer for all who use them: On Wednesday, city council unanimously approved a safe passing ordinance that requires drivers to keep a minimum of three feet between motor vehicles and all "vulnerable road users," and demands that commercial drivers give a six-foot berth.

That definition includes pedestrians, physically disabled persons, stranded motorists, construction and maintenance workers, cyclists and others utilizing a "human-powered wheeled vehicle," plus mopeds and scooter operators and horseback riders.

The ordinance, which takes effect immediately, punishes drives who come too close to, unsafely overtake or harass, intimidate or throw objects at a vulnerable road user, with a $500 fine.

"As a city, we need to protect everyone and anyone who uses our roads," said Mayor Annise Parker in a statement. "This ordinance will make our city even more attractive to those who want to enjoy traveling in forms other than by car."

"BikeHouston is pleased to see this ordinance pass and proud of the Mayor's continued efforts on helping Houston become a more bicycle-friendly city," said Kathryn Baumeister, chair of BikeHouston, a volunteer group that has pushed for city legislation.

"Houston is a city of cars, but also has a big population of people who rely on cycling for transportation and recreation. We feel it is important for cyclists and drivers of automobiles to respect one another on the road. This ordinance will help provide a measure of safety for the vulnerable road users."