San Francisco is giving the public three opportunities in the next week to sound off on its proposal to charge rush-hour tolls to drive into the busy downtown.

It’s an idea that gets a hot reaction from some drivers, but the practice is catching on in some big cities in Europe and Asia as a means to reduce traffic congestion.

The idea is simple: Get motorists to shift their driving hours, or get them to switch to carpools or public transit. The catch: No city in America has enacted congestion pricing on its roads.

The San Francisco County Transportation Agency is considering a fee of $3 per vehicle per trip across congestion zone lines between 6 and 9 a.m. and 4 and 7 p.m. on weekdays.

Here’s the time and place of public workshops to learn about and comment on the proposed alternatives.

• - 5:30 to 7 p.m. tonight (Dec. 2) at the San Francisco Main Library, 100 Larkin St.
• - from noon to 1 p.m. Friday, an interactive session on the Web by authority staff members. Find viewing details at www.sfmobility.org.
• - 5:30 to 7 p.m. Monday at the San Francisco Ferry Building,  Port Commission hearing room second floor, 1 Ferry Building.

Visit www.mobilitysfta.org to learn more about the options.

Do you think congestion pricing is heavy-handed social engineering, or is it smart planning to protect cities from traffic and air pollution? Share your comments below.