February 21 , 2003, #6

Let's Walk & Roll

Why Alameda Drives 25 (part 1)

Take the following 25 MPH challenge: the next few times you drive through Alameda, make sure you check every intersection for people waiting to cross the street and stop to let them. Pay attention to traffic as well, and don’t forget to stop for the lights. How fast are you going when you are actually able to do all these things? You’ll find it’s nearly impossible at any speed over 25 MPH.

Ask most drivers around town what they think about the 25 MPH speed limit and most will say that they think it could be a little higher. Many will tell you that they can easily drive 30 or 35 MPH with no problem. Ask people in any given neighborhood what they think about being able to walk and bike safely and most will say it’s vitally important to the quality of life in their neighborhood and city. Judging from the public comment on the new Catellus Housing project, Alamedans are not incredibly impressed with the “sound wall” that is be built to keep the new housing quiet.

What do all of these statements have in common? They are all intricately inter-linked to vehicle speed. Following is a quick primer on speed. Next month, we’ll look at the effects of these issues on the community that we hold close to us.

Tackling the easiest issue first…noise. The noise level of rubber tires on the road doubles every 10 MPH. Tires meeting the road is the greatest noise producer of the driving experience. In the case of the Catellus project, the Environmental Impact Report that was prepared for the new Tinker Avenue extension that will run right past the housing specifically cites the recommended 35MPH speed limit as necessitating a sound wall.

The safe driving/safe neighborhoods discussion is a bit more troublesome. Some would say that any given road in Alameda could be safely navigated at 35 MPH. However, this assumption ignores the fact that our streets are public space and to be also available for the safe use of walking and bicycling. People use the streets for many activities, including walking and biking.

At 35 MPH, it takes an average vehicle 136 feet to stop (more if you’re driving a truck or SUV) which includes reaction time. At 25 MPH, the distance is 85 feet, nearly half the distance. This is why it’s so difficult to drive over 25 and be able to stop for pedestrians. At 35 MPH, you need half a football field to stop in time.

Now consider the following: at 20 MPH, the survival rate for a pedestrian struck by a car is 95%. At 30 MPH, it’s 60%. So not only is stopping for people nearly twice as hard at 30-35 MPH, but if you hit someone, you are a third more likely to kill them than you are keeping your speed (at or) below the posted speed limit. Being drivers who care about safety in our neighborhoods is ultimately the solution to the problem of speeding.

Interested in local transportation issues? The League of Women Voters will be sponsoring a transportation information forum on March 20 (7pm) at City Hall. Call the League for more details: 865-6032.

Jeff Swatman is the Alameda Police Department Traffic Sergeant. If you have questions regarding pedestrian/bicycle safety, please call him at 748-4508 extension 3342. John Knox White and Audrey Lord-Hausman work with Pedestrian Friendly Alameda (www.pedfriendly.org) and BikeAlameda (www.bikealameda.org).

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