Are the speed radars on streets accurate?

Age usually throws the reading off on a speedometer. But 1 to 2 mph off is within tolerance. If you have a gps that tells you how fast you are going, then you may be able to check your speedometer against that as they're pretty reliable when it cmes to speed. If the gps matches the speed on the street radar then you know which in the equation is off (speedometer). Age usually throws the reading off on a speedometer. But 1 to 2 mph off is within tolerance. If you have a gps that tells you how fast you are going, then you may be able to check your speedometer against that as they're pretty reliable when it cmes to speed. If the gps matches the speed on the street radar then you know which in the equation is off (speedometer).reliable when it cmes to speed. If the gps matches the speed on the street radar then you know which in the equation is off (speedometer). Age usually throws the reading off on a speedometer. But 1 to 2 mph off is within tolerance. If you have a gps that tells you how fast you are going, then you may be able to check your speedometer against that as they're pretty reliable when it cmes to speed. If the gps matches the speed on the street radar then you know which in the equation is off (speedometer).