National Motorists Association Blog

By California NMA Member Stacey Charlton 

Speed bumps, humps, and cushions are the common names for traffic calming/control devices that lie in the street in both a vertical and horizontal plane to make drivers slow down. The many disadvantages to these road hazards are not always clearly disclosed through a city’s public works, traffic engineering, or streets department. This series of blog posts will help uncover the cons of speed calming/ control devices and hopefully help neighborhood groups arm themselves with information that is difficult to obtain elsewhere.

To fight these city installed road hazards, you must first know the difference:

Speed Bumps are hard, back-breaking strips that you find in a grocery store parking lot or places where the speed limit is five to ten mph as on college campuses. Bumps are not suited for roads where traffic is 25 miles per hour.

So why do the road hazard warning signs on residential streets say ‘Speed Bump’ instead of ‘Speed Hump?’

Let’s first start with the definition of a speed hump.

Speed Humps are generally 12 to 14 feet long, and they span the width of the road and range from three to four inches high. The shapes can be parabolic, circular, or sinusoidal. Speed humps are typically placed on residential streets, mid-block between intersections, and one is usually not effective. Two- or three-speed humps might need to be installed and are generally set 350 to 550 feet apart on long stretches of a street because drivers might speed up after traversing them. Warning signs are typically used but are placed a bit ahead of the road hazard. The actual humps may sneak up on you during the night or at sunset/sunrise.

Speed Cushions are similar to humps but are narrower, and they span the width of the road with slots in between for the tires of large first responder vehicles. Although cushions are far from the soft pillow-like term they sound like, they generally have cutouts that supposedly allow emergency vehicles to pass through.

I say ‘supposedly’ because, in some cases, traffic engineers have designed the cutouts to accommodate the front tires but not necessarily the dual rear tires of these emergency vehicles. For example, in the photo below provided by the Public Works department of the town I live in, the cutouts seem wide enough to accommodate the fire truck passing through without issue. But if you notice, they only show the front tires and not the back. Also, the cutouts might not be either when traffic-calmed streets are not as wide. Vehicles with dual rear tires would be unable to pass through the narrow cutouts, thus causing damage to the fire equipment.

In my work against speed control devices in my Hillsborough, California neighborhood, I have had to educate myself on these devices and have come up with a list of reasons cities should NOT use them.

Back to the question I posted before, Why does Public Works put up road hazard warning signs that say “Speed Bump” when the road hazard is clearly a Speed Hump?

It’s because officials at the California Department of Transportation think residents are not smart enough to know the difference. So, even though bumps are different from humps, here is how the DOT phrased it.

“However, this difference in engineering terminology is not well known by the public, so for signing purposes, the terms are interchangeable.” 

Dear dot.ca.gov, I think we are smart enough to figure out the difference between a bump and a hump without an engineering degree.

Listing all of the disadvantages of speed control devices will take a few blog posts. Still, my biggest objections are how speed control devices affect first responder safety, their vehicle & equipment safety, and the response time of the police, EMTs, and firefighters.

Emergency Response Time May be increased to Emergencies

Many fire trucks, including those that service my street in Hillsborough, CA, have side-by-side tires in the rear. The dual rear tires will not fit through these narrow cutouts. This vehicle could easily not have enough clearance for tires to fit, which could cause sidewall damage. Sidewall damage to a tire is not always visible and can lead to tire blowouts.

When you call 911, you want responders to arrive lickety-split to help you or a loved one or protect your property. I have been taught and try to practice compassion whenever I can, and subjecting those in need to increased response times that could be the difference between life and death is wrong.

Speed Cushion Cutouts Increase Chances for Emergency Vehicles and SUVs to have Head-on Collisions with Oncoming Traffic

Cutouts or speed slots are typically placed in the center of the road, meaning our emergency vehicles must swerve into oncoming traffic to use them. This increases the chance of a head-on collision. Other drivers will sometimes swerve into the other lane or gutter, so at least one of their tires is not going over the speed control device.

Rear Dual Tires on Emergency Vehicles may be too wide to fit through the Speed Cushion Cutouts

When I mentioned that I was concerned about emergency response time to my home due to multiple speed cushions being installed, my city’s public work’s department responded by stating that emergency response time would not be affected because they had installed cutouts in their speed control devices. These cutouts look narrow and not well marked to me. I had heard that our city’s fire trucks had dual tires, which are much wider, so I reached out to our Fire Chief Bruce Barron, and he confirmed, “All of our Apparatuses (Fire Engines, Fire Truck, Type 6 and Mechanic Vehicle) have dual rear tires. This is required because of the gross vehicle weight rating.”

I emailed back to my city’s public works department and wrote again that I am concerned about the narrow cutouts because of the dual tires on the fire trucks. The Public Work’s people then sent me the two photos below of the fire truck passing smoothly through the cutouts as a way to appease me.

But if they had read my email, they would have known it was not the front tires that concerned me but the dual rear tires that are much wider that made me take a pause for the safety of our local firefighters and those whose emergencies they were driving too.

Causes Damage to City Equipment

City Equipment such as fire trucks has been damaged on route to emergencies. In Tampa, Florida, a fire truck broke its rear axle on a speed hump. Is emergency care going to get to your house quickly with a broken axle?

Seeing as there are multiple speed bumps before a stop sign, this would put undue pressure on the rear axles and tires of the fire truck or ambulance.

Daily fire truck checks are conducted: lights, sirens, oil and fluid levels, equipment on board, the pump, and air brakes (if applicable). Checking underneath the firetruck to check on the condition of the frame and the U-bolts/attachments that keep the rear axle on the frame of the truck is not part of that daily truck check. That would be done annually by a certified mechanical technician.

There is a concern that when a city or town installs these devices, U-bolts/attachments could loosen on the fire engines, fire trucks, type 6 and mechanic vehicles, and ambulances. This could endanger the lives of our firefighters and EMTs that are unable to use the narrow cutouts on residential streets safely.

David Dock, EFO, chair of the International Association of Fire Chief’s Emergency Vehicle Management Section, states, “The apparatus is how we do our job. The apparatus is what gets us to the call to help the people we need to serve. So, if this fails, we all fail.”

In these two linked articles, you can better understand how wide the dual tires are on fire trucks. These terrifying stories can show what happens when outside forces break off the U-bolts from the rear axle of emergency vehicles.

• Northern New York Firetruck Loses Its Wheels on the way to Call
• The wheels on the truck…fall off?

Delayed EMT Services in Route TO the Hospital

Speed control devices make it difficult for EMTs to administer extended life support and almost impossible to intubate patients. They must stop life-saving measures as they traverse the speed control devices. EMT drivers may take longer routes to the hospital to avoid streets with speed bumps for the patient’s safety. Also, the EMT with the patient in the back of the ambulance is generally not buckled into a seat belt, so she/he could easily be injured if tossed around trying to save someone’s life.

Delayed Emergency Response Services in route TO a Sudden Cardiac Emergency

County of Sonoma, CA states in its Speed Hump Policy that “Emergency response times are delayed approximately 10 seconds per speed hump.”

If a person has a sudden cardiac arrest (SCA) event, they need a defibrillator within five to six minutes. The rate of survival decreases with every second emergency response is delayed, which means that delays due to speed humps can cost people their lives.

City of San Mateo, CA Neighborhood Traffic Management Program states that Speed Cushions DO impact Emergency Response Times.

In addition, the city of Marin, California, states under disadvantages of speed humps that, “Speed humps have a documented negative impact on the response time of emergency vehicles (up to a 10-second delay per hump).”

Because these three counties state that emergency response time WILL be delayed, I find it interesting that our fire chief said to me that emergency response time would not be delayed when there are two-to-three-speed control devices in between my house and the fire station/hospital.

Traffic Calming Devices can Delay Fire Department Arriving before House Fire Burns beyond its Flash-Over Point

Captain Scott Brown of the Orange County, CA Fire Authority noted that it takes only about five minutes for a fire to burn beyond its flash-over point and quickly spread. If speed humps delay fire response by up to 10 seconds per speed hump, then the fire department may not arrive before your house fire burns beyond its flash-over point.

In Part 2 of this series on How to Fight Speed Bumps, Humps, and Cushions, I will explore pain and damages that can occur to personal vehicles, emergency equipment, and a person’s lumbar spine.

• If you have had a negative experience with a traffic calming device, please write about your experience in the comment section below.
• Make sure you are on the mailing list regarding all updates and votes regarding these speed control devices for your community.
• To gather more information about your local situation, ask your public works department for all letters, emails, and memos related to the speed control devices that have been or will be installed. They legally have to give you this information; however, they will black out the residents’ email and phone numbers but can leave the person’s name and address on the documents as they are public records.
• Do an internet search for your county or city information on speed calming devices/speed bumps, humps, and cushions booklet and list the cons they describe. Is delayed emergency response time one of those cons?
• Email the National Motorists Association (nma@motorists.org) the link to your discovered local traffic guide pdf so we can compare it to other municipalities.

In the meantime, here are two questions to contemplate:

• Which of the above topics concern you about speed calming devices?
• Does it worry you that speed control devices can affect emergency response time?