Yeah safety is important but 100kmph seems very average speed.expressways are getting built to reduce travel time. Not all accident happens because of over speed. Pot hots, sharp turn, animal crossing, human crossing, tire busting are some of major one. If safety is that much of concern why not making 6 airbags, 5 star ncap rating mandatory. The government is just milking money placing these cameras at random place which no advertising of speed limit or may be putting a small board somewhere behind the tree. We gives lots of tax when we buy vichcle and on top of it tolls, pollution cert. But it's very difficult to drive peacefully. Not on expressway, I have seen camera with speed limit 30kmpl. why not building overbridge, one way lane or some alternate solution. Most of the people drive fast because they have control on there vehicle..not taking about drink and drive. Any way drunk person will not care about these speed limits.