The simple speed bump, or ‘traffic calming’ measure in city planner speak, has been present on UK roads for closing on 50 years. Whilst their intention as a low cost method to prevent speeding may have been virtuous, their generic application of effect has caused problems.
Every driver crossing one has to slow down considerably or risk damaging their car. So rather than being a method of slowing down speeding drivers, they are instead a punishment to all drivers regardless of their intent to speed or not.
Room for Improvement
The effects of speed bumps have been examined in multiple studies which concluded that they waste money, cause pollution, damage vehicles, and harm people. The list of negatives is not insignificant:
- Damage to vehicles
- Impediment of Emergency Vehicles
- Increased noise
- Higher pollution levels
- Can cause spinal damage to occupants
- Extra signage and Lighting costly and intrusive
- Increased traffic on surrounding roads through evasion.
A few different types of speed bump have been subsequently developed, either as an attempt to improve the original design or modify it for a slightly different use.
The Speed Bump itself is the oldest version and most severe. Usually only a foot across and 3-4 inches high, they stretch across the entire road width and rise sharply forcing drivers to slow considerably to cross over them. Travelling at anything over minimal speeds can result in suspension damage, but they are now relatively uncommon and found mostly in car parks and on private land.
The evolution of the ‘Bump’ was the ‘Hump’, which combined a wider construction with a less severe incline to produce a gentler curve. They have replaced bumps to be the standard type commonly found on roads as they still fulfil the core function of slowing down traffic, but with less of the potentially damaging consequences.
A further evolution was the Speed Cushion, which was designed to allow larger vehicles (specifically emergency service vehicles) to cross them almost unimpeded. They typically sit in the centre of each lane, with sometimes additional cushions inbetween lanes to cover wider roads. The gaps between them and their tapering edges allow larger vheicles to cross with little trouble, and smaller sized cars can reduce their severity too if lined up correctly and travelling at a moderate speed.
A larger relation to the others is the Speed Table, which can also include a crossing known descripitviely as a Raised Pedestrian Crossing. These designs extend the top of the hump considerably, allowing enough space for the crossing to potentially sit on top of it while still forcing drivers to slow down when both entering and exiting. They vary in size significantly and can often encompasse entire junctions.
After this there are the numerous designs of lumps and bumps and shapes, all claiming to do the job a little bit better than what came previously - but all still opertaing on the same basic principle of placing a solid obstacle in the path of a vehicle that causes excess wear and tear even at relatively low speeds.
There are also a few powered versions of speed bumps in use around the world; involving adjusting the height of the road surfaces to allow certain vehicles to cross with restriction when necessary. Generally they are far too complex and expensive to ever be viable for general road use.
Same goal, Different approach
Advances in material technology have now found an innovative way to continue using speed bumps, but modify their function to only affect those that need to be slowed down.
Asphalt or concrete is typically used to form bumps as the materials are tough enough to resist the constant impact of multi-tonne vehicles, but uniquely the Intelligent Speed Bump is formed from a super hard wearing plastic tube that is flexible.
This container depresses under pressure and when empty would provide no obstacle to a vehicle whatsoever. To form the obstacle, the container is filled with a non-Newtonian fluid which hardens under a sufficient enough impact, triggering at a given speed. By varying the quantity and chemical make up of the fluid you can control at what speed the hardening provides the resistance required to encourage drivers to slow down.
Any vehicle travelling below this set speed can cross over them without slowing down as the fluid stays in its liquid state, but as soon as it suffers a greater impact by a vehicle travelling at a higher speed it functions as a normal speed bump.
This means the bump will only slow down those who need to be slowed, while those who are obeying the traffic laws can travel without concern - and reverse all the negatives seen with conventional speed bumps. Liquid Speed Bumps will ease traffic congestion by allowing to flow at a consistent rate, reduce pollution caused through inefficient slowing down and speeding up, and improve reduce repairs and increase the lifespan of peoples vehicles by causing less damage.
It’s a great example of a new technology improving the driving experience for road users, while reducing costs and improving the environment at the same time.