Speed limit signs on roads are a common sight in every country across the globe. Their basic purpose is to control traffic speed and make the roads safer for motorists, passengers and pedestrians alike. Often the signs indicate a fixed maximum speed although signs for variable speed are also common. Variable speed signs can be both mandatory and advisory in nature.
Mandatory signs are always enclosed in a red ring thus indicating their importance and inalienable category. These should be strictly followed if you want to stay within the law and drive safely. However, they can also be advisory in nature. These signs are installed as a temporary measure to warn motorists about an impending danger for a specific period of time.
Variable Speed Road Signs
As mentioned above, all mandatory signs are enclosed in a red ring. Any other sign is considered advisory in nature and it is up to you to interpret it the way you like. Certain carriageways also have an automated system with light signals for controlling traffic speed. Here too, a mandatory signal will be enclosed in a red ring whereas advisory signs will be indicated by flashing amber lights.
Purpose of Having Variable Speed
The basic purpose is to allow motorists the freedom and flexibility to travel at an appropriate speed depending on the prevailing weather conditions or road condition. It is also an effective way of harmonizing the total traffic flow on a particular carriageway so as to prevent flow breakdown in case of high traffic volume.
Controlling speed also has an impact on the environment and mandatory signs and advisory signs can indeed make your immediate environment a better place to live.
Variable Speed for Safer Roads
Inclement weather can turn even the best-maintained roads into fatal traps for motorists. Rain, ice, snow, strong winds, dust storms etc not only reduce visibility but also make the roads slippery or unsafe.
Variable signs installed at the entry of carriageways and tunnels are an indication that the road ahead is not in best conditions and you should reduce speed for your own safety. Mandatory variable signs (enclosed in a red ring) indicate it is compulsory to reduce speed whereas an advisory sign leaves the decision on you (in case the road is not severely affected but still needs cautious driving).
Variable Speed for Better Traffic Control
Advisory signs and mandatory signs are also an effective way of better traffic management. It is not always safe or possible to follow the maximum speed limit on all major or minor thoroughfares. Even on wide major carriageways, driving at maximum speed can lead to breakdowns or accidents that will create traffic bottlenecks. A variable speed sign is used to reduce congestion severity and duration and also to avoid accidents as much as possible.
Variable Speed for Better Environment
Controlling speed also goes a long way in mitigating the harmful environmental effects of traffic such as excessive noise and emission of toxic fumes. When people drive in a controlled manner, there is less honking of horns. And when cars start and stop less frequently because of traffic congestion, there is less emission of polluting fumes in the environment.