Environmentally unconscious speed limit signs

Speed limit signs are necessary for safe sharing of roadways. However, in many instances speed restriction signs seem to be over implemented and placed at positions where they contribute to environmental damage.

Aside from neccessary instances where signs are placed to slow traffic around areas such as where children frequent, schools, child care centres, hospitals, animal crossings etc, sometimes signs are placed where they give brief changes in cruising speed that seem unnecessary. Some of these signs may be old signs that have not been removed. Why would that even matter? Aside from the inconvenience of slowing down, speeding up and concentrating on speedometers several times, (which takes the attention away from the road), which is where it should be when driving; the speeding up and slowing down involves accelerating, (consuming extra fuel and creating more harmful emmissions). And braking involves loss of momentum of the vehicle, (as well as extra mechanical wear and tear), which needs to be made up for by extra acceleration.

So what's the big deal about that? Well, when you consider the number of vehicles involved that pass one such sign, the environmental impact is significant, (not to mention the safety issue of regularly taking ones attention off the road to concentrate on checking a speedometer for fear of breaking a law). But an even worse kind of environmental assault comes from signs that allow a higher change of speed placed on, or at the foot of, an ascending climb on hills. Granted, sometimes some of these signs are neccessary due to the areas that they protect, but sometimes they are not. And the amount of extra energy involved in forcing a vehicle to accelerate up hill is huge; which can be easily demonstrated and felt, by physically running up a hill! Try it for yourself to test this out if you are in doubt!

Speed limits are normally zoned, but what about having different speed limits on down and up hill runs, depending on the direction travelled? Of course it is considered to be more dangerous to travel faster on down hill runs, but it is a loss of momentum to travel slow downhill and have to push an engine harder to climb the other side of a valley. Often bridges are a consideration in valleys also. Perhaps bridges could be wider and perhaps separating barriers might be safer. But extra construction using more raw materials may defeat the saving. Weighing up the benefits would need to be calculated. One may think that it is not such an issue now with more electric vehicles and so on, however, all those vehicles require energy to recharge. So how much energy to recharge, and how often charging is required depends largely on how much energy is expended in the first place.

When the environment is considered in the reasoning of where to place speed restriction signs, it will help to reduce overall emmissions when it becomes normal for municipalities to consider the environment and effeciency of travel when deciding where to place signs in the first place.