These elements, in general, calm the traffic on the street on which they are installed, but they can cause different inconveniences:
Excessive discomfort for vehicle users (be they cars, vans, motorcycles, bikes, or buses).
Physical discomfort in professional drivers who work in the city.
More noise in the environment is generated by the shock in the vehicle’s suspension when passing over the shoulder.
A slight increase in consumption and pollutant emissions due to reduced speed and then accelerate again (many more times) instead of constantly traveling along the entire street.
Possibility of increased wear and the appearance of play of the chassis elements and the vehicle’s running gear (tires, damping, steering).
Driveway speed bumps are helpful where the risk of being run over is high, and other measures fail, but they should not be installed in any way, ignoring the inconvenience. This is why after the first experiences with a multitude of shoulder designs without any regulation that regulated them, an attempt was made to find a certain balance in the speed reducers’ design and characteristics.
You cannot place shoulders one after the other: there should be a separation of at least 50 m
Speed Reduction Bumps Have Their Norm.
Technical Instruction was published to install these devices that specify what types there are, where they can be placed and where they cannot, what geometry and dimensions they must have, and how they must be built and marked.
This instruction has a limitation: it is only mandatory on the State road network but not on regional roads or city streets (unless it is a crossing). Even so, its application is highly recommended since the content of this instruction is by reasonable technical consensus to have balanced speed reducers that fulfill the intended function and that at the same time are not counterproductive.
Technically, it is considered that there are two types of speed bumps: those with a trapezoidal cross-section or elevated crosswalks and those with a circular cross-section or donkey’s back. The former admits a subtype called combined or pillow when they arrive from sidewalk to sidewalk, covering the entire width of the road. In turn, both can be executed in situ or prefabricated.
This is what painting should look like on elevated pedestrian crossings
The distance between consecutive speed bumps must be between 50 and 200 m: there cannot be one shoulder band following another less than 50 m apart.