Imagine the following situation: a narrow residential street with vehicles passing by at speed incompatible with safety. What is the ideal solution pointed out by the residents and usually adopted by the transit agencies? Build a speed bump like speed bumps Columbus. In particular, I do not consider the alternative inappropriate under certain circumstances. The problem is the way it is built.
They are transverse undulations and can be used where it is necessary to reduce the speed of the vehicle imperatively, in cases where a technical study of traffic engineering shows a significant index or potential risk of accidents whose determining factor is the speeding practiced in the place and where other traffic engineering alternatives are ineffective.
It is not enough to gather the necessary material and build a spine; the implementation of the transversal undulation on the public road will depend on the express authorization of the Transit Authority (director/president of the transit agency) with jurisdiction over the road.
There are two types of speed bumps, Type A and Type B. The first can be installed in places where there is a need to limit the maximum speed to 30 km/h on highways with urbanized sections, on urban collector roads, and in places that are, in rule, low movement. The second type can be installed on a local urban road to reduce the speed to 20 km/h, as long as there are no regular lines of collective passenger transport.
If the spine is installed close to an intersection, a minimum distance of 15 meters from the curb alignment or the edge line of the transversal road must be respected. The Type A spine should be 8 to 10 cm high and 3.70 m long, while the Type B spine should be 6 to 8 cm high and 1.5 m long. In both cases, the width is the same as the track.
In addition, there is a requirement for signage, that is, there must be “maximum speed allowed” signs in place, two “protrusion or spine” signs, one before the transverse undulation and the other with a position arrow next to the undulation, which it must be painted completely or with stripes interspersed in yellow. It is strictly prohibited to use tacks, studs, and similar devices applied across the street, which are those famous yellow “bricks” that are sometimes used to replace the spine.
One year after the implementation of the transverse undulation, the Authority with jurisdiction over the road must evaluate its performance using a traffic engineering study and study another engineering solution when its effectiveness is not verified. Realize the complexity of installing something relatively simple on the road, which aims to reduce accidents.
In cases where people build the spine, accidents can occur due to the lack of technical requirements and proper signage, and those who improperly place the obstacle will be held responsible. The same happens with some transit agencies that objectively respond to possible damages caused to citizens (art. End up building a “speed bump” that will break some bones.