Are "Sleeping Policemen" the Solution to
Speeding in Our Neighborhoods?
A Saranap resident told us recently that people on her street have been talking about having speed bumps installed as a way of slowing down traffic in their lower-Saranap neighborhood. She asked us to look into this possibility. This is what we learned. In a nutshell: The county doesn’t install them, for two good reasons, and doesn’t consider them an “official traffic-control device.” And the county’s Neighborhood Traffic Management Program doesn’t really offer any alternatives.
Speed bumps – known in some places as “sleeping policemen” – are one of several devices described in the Neighborhood Traffic Management Program, a “community-based approach to traffic calming.” Speed bumps are three- to six-inch rises, or “undulations,” in the pavement, or mats installed on the pavement, that usually measure one to three feet across. They’re generally found on private roads and parking lots, not public roadways.
In the same category as speed bumps are speed humps and speed tables. Both are three- to four-inch rises measuring 12–14 feet. The difference between the two is that there’s a flat surface on the top of a speed table to accommodate a crosswalk.
All are effective at “calming” traffic. Speed bumps typically slow traffic to 5 mph or less and speed humps and tables reduce speeds by five to 10 mph – and therein lies one of the reasons the county won’t install them: They have the same effect on emergency vehicles. The other is that the county would be liable if any problem occurred because of their use – an accident or damage to a vehicle, for instance.
So what alternatives are there?
Options for traffic calming on narrow two-lane streets like those in the Saranap are pretty much limited to stop signs and various approaches, like traffic circles (roundabouts), to controlling traffic passing through intersections, which isn’t the problem this woman and her neighbors are grappling with.
Lowering the speed limit isn’t an option. The speed limit for residential areas is set at 25 mph by the California Vehicle Code, and dropping the speed limit doesn’t work anyhow, notes the county’s “FAQs – Traffic.” “Drivers drive at a speed they feel is comfortable.”
What about “Slow – Children at Play” signs? It turns out that these and signs like them are not permitted on public roads. “The message this sign gives to children is that it is acceptable to play in the street, which is contrary to the California Vehicle Code,” the county says in its traffic FAQ. We haven’t heard of anyone from the county removing these signs, though, and we’ve seen the same ones posted in some Saranap neighborhoods for months.
Public Works will sometimes park a portable radar-speed trailer in a neighborhood for a day – if the street meets their criteria and there’s a place to park it. These are effective while they’re in place, but “Drivers generally return to previous speeds soon after the sign is moved,” the county observes in its traffic-management program document.
The bottom line, then, is that though they’ve been shown to be effective, “sleeping policemen” aren’t an option – and in fact, there doesn’t seem to be anything the county can do to reduce speeding in residential neighborhoods.
Click here to read the county’s “FAQs – Traffic.”
Click here to download the county’s 77-page Neighborhood Traffic Management Program document.
Speed bumps – known in some places as “sleeping policemen” – are one of several devices described in the Neighborhood Traffic Management Program, a “community-based approach to traffic calming.” Speed bumps are three- to six-inch rises, or “undulations,” in the pavement, or mats installed on the pavement, that usually measure one to three feet across. They’re generally found on private roads and parking lots, not public roadways.
In the same category as speed bumps are speed humps and speed tables. Both are three- to four-inch rises measuring 12–14 feet. The difference between the two is that there’s a flat surface on the top of a speed table to accommodate a crosswalk.
All are effective at “calming” traffic. Speed bumps typically slow traffic to 5 mph or less and speed humps and tables reduce speeds by five to 10 mph – and therein lies one of the reasons the county won’t install them: They have the same effect on emergency vehicles. The other is that the county would be liable if any problem occurred because of their use – an accident or damage to a vehicle, for instance.
So what alternatives are there?
Options for traffic calming on narrow two-lane streets like those in the Saranap are pretty much limited to stop signs and various approaches, like traffic circles (roundabouts), to controlling traffic passing through intersections, which isn’t the problem this woman and her neighbors are grappling with.
Lowering the speed limit isn’t an option. The speed limit for residential areas is set at 25 mph by the California Vehicle Code, and dropping the speed limit doesn’t work anyhow, notes the county’s “FAQs – Traffic.” “Drivers drive at a speed they feel is comfortable.”
What about “Slow – Children at Play” signs? It turns out that these and signs like them are not permitted on public roads. “The message this sign gives to children is that it is acceptable to play in the street, which is contrary to the California Vehicle Code,” the county says in its traffic FAQ. We haven’t heard of anyone from the county removing these signs, though, and we’ve seen the same ones posted in some Saranap neighborhoods for months.
Public Works will sometimes park a portable radar-speed trailer in a neighborhood for a day – if the street meets their criteria and there’s a place to park it. These are effective while they’re in place, but “Drivers generally return to previous speeds soon after the sign is moved,” the county observes in its traffic-management program document.
The bottom line, then, is that though they’ve been shown to be effective, “sleeping policemen” aren’t an option – and in fact, there doesn’t seem to be anything the county can do to reduce speeding in residential neighborhoods.
Click here to read the county’s “FAQs – Traffic.”
Click here to download the county’s 77-page Neighborhood Traffic Management Program document.