Speed humps – a safer pace of life.

Many Kiwis know them, not necessarily that fondly, as “judder bars”, but they’re also called speed humps, sleeping policemen, speed bumps, and even speed ramps.

Brian Townsend from the TransQuip team has the answers to some of the speed hump questions we get asked most often. Along with some great tips. Check out his helpful video or read more on the blog below.

Why have speed humps?

Speed humps are mainly used to slow and calm traffic in car parks – especially entranceways – and narrow streets and residential areas, and to increase the visibility of schools and crossings. They help protect pedestrians and other traffic and generally encourage drivers to take greater care and slow down.

Used to keep speeds to around 10km or even 5km, speed humps are an important part of urban planning. On top of that, they’re often included in Health and Safety protocols for supermarkets and other commercial sites with heavy vehicle traffic.

Speed humps became a regular part of Kiwi life around the late 1970s/early 1980s and were invented in the USA by physicist, and Nobel Prize winner Arthur Holly Compton, in 1953 who got sick of cars speeding by his university!

Are there different kinds of speed humps?

Yes.

Rubber moulded speed humps are practical, robust and can be recycled at the end of their working life.

Available in a variety of lengths, (1.65 to 1.83 metres) these speed humps can also be lifted and re-sited, according to the site’s needs. Features include a rubber cap which keeps the ends tidy.

Available in weather-resistant high-vis yellow and black, they are a professional traffic calming solution.

Moulded asphalt and concrete versions laid in the road are also used. These require a greater level of expertise (a professional contractor) to install them. They also generally require the road or site area to be closed for a period of time – which can be a nuisance and interrupt business. They can’t be recycled, moved around or re-purposed at another site.

How do you install the rubber speed humps?

It’s actually fairly straightforward. All you need is the steel pins – which are about 12mm diameter and have a flange head. (You can order these when you purchase your speed humps.) These are driven into the asphalt down to around 250mm.

Tip: Make the job a bit easier by drilling down into the hard base to give the pins a decent start.

Moveability for convenience

If you have to remove and change the position of the rubber humps you can – by drilling off the flange head. Take the pins out or drive them into the ground.

Concrete surfaces

When you’re dealing with concrete dyna bolts are the best solution for anchoring the speed humps. Check the manufacturer’s instructions to get the right depth of hole. You need to ensure that the installed, tightened dyna bolt is well below the top surface of the speed hump to avoid any damage to vehicles’ tyres. (Which wouldn’t make you very popular.)

How many speed humps are best?

Every site needs to be carefully assessed to balance safety and accessibility. (Also taking into consideration the types of vehicles which need to have access and how often.)

General weather patterns, the levels of the site, and even visibility and lighting need to be thought through.

As a rule of thumb, two sets of speed humps installed relatively close to each other are most efficient for slowing traffic down. You can check out more details about traffic calming here.

Tip: A study in Sweden concluded that the risk of fatal injury at 50kph is twice as high as at 40kph and five times as high as at 30kph (Rosén and Sander, 2009).

If you have more questions on speed humps, talk to the TransQuip team today. Our experts will be happy to help.