I was issued a ticket for Speed Against a Municipal Sign for driving over 30km/hr in a playground zone. The officer had no laser and no radar; she flagged me over, saying "The speed limit here is 30--you were not doing 30." I can't say whether I was doing 31 or 51; my best guess based on the location I was pulled over would be somewhere between 30-40. What does the law say surrounding this? Would I have grounds to dispute this ticket?
The law says that a municipality may regulate speed by enacting a bylaw and placing signs to limit the speeds of vehicles on municipal streets. If you pass such a sign your vehicle's speed cannot legally exceed that shown on the sign. If it does, by one or by one hundred, the court may choose to convict.
The courts will also accept estimates of speed from both police officers and the general public where the witness is credible and has knowledge and experience that would allow them to guage speed. Most drivers would have this capability through the experience of operating their own vehicle. Police officers have this capability as well as practice with it as they estimate speed and then confirm that speed with either a laser or radar in the course of their enforcement duties.
It appears that you are not sure of your speed and that it could be over the limit. Being honest, if you cannot convince the court with certainty that it was 30 or less, you will have to dispute on other grounds. These may be that there was no bylaw, there was no sign, the sign was not applicable in the circumstances or the officer was mistaken in the estimate.