x8pg2qr wrote:igstar wrote:How can they enforce speed limits for bicycles when speedos are not compulsory?
Cars have to follow several laws when parking e.g.:
http://www.vicroads.vic.gov.au/Home/Saf ... arking.htm
They still have to be followed even though rulers/tape measures are not compulsory in cars.
I don't think you are using a valid comparison. When you have parked the car you have the time to make an estimate of a fixed distance in an environment where you can compare it to surroundings.
When moving, you are surrounded by other moving objects, all going at different speeds. Your perception of speed is also skewed by hills and wind. Your mind is also focused much more on its surrounding than estimating the speed. Maybe try and see for yourself how much harder it is to estimate the speed than the distance.
In fact, humans have the tendency to underestimate speed and overestimate distance!