Speed limits are a fairly simple concept. They set the legal speed at which a vehicle can be traveling on a road. However, there are various speed zone signs, some with different rules to follow. Knowing them will help you to become a safer driver, and potentially save you from expensive tickets.
Speed limits were first set at 10 mph in the United Kingdom in 1861. With the advent of faster vehicles and the production of more vehicles, speed limits, along with the number of roads that used them, increased.
Typically in orange, construction zone signs set their own limit that differs from the established speed zone. For example, a sign that reads "slow" means you should not drive above 20 mph, and even 15 mph to be on the safe side. Pay attention to these signs, as violations double in construction zones.
Speed Zone Ahead
The "speed zone ahead" sign indicates that the road you are driving on will shortly see a change in the speed limit. For example, if you are driving on a road with a limit of 60 mph, a speed zone ahead sign will read "30 zone ahead," which means you must reduce your speed to 30 mph. These signs allow you to anticipate the change and adjust your driving accordingly so you won't be caught going over the limit.
School zones have different speed limits during times of day when children are on streets near schools. The speed limits are usually within 15 to 25 mph and are generally enforced from around 8:00 a.m. to 9:30 a.m. and in the afternoon from 2:00 p.m. to 4:00 p.m.
Highway and Freeway Zones
Typically with higher speed limits than business zones, freeways and highways are designed to get travelers from point A to point B more quickly. With expanses of road and little in the way of houses and other businesses, these stretches allow for speeds in excess of 70 mph in some cases.
A liberal estimate is that driving 5 mph over the limit in most zones is safe and will not cause you to get a speeding ticket. A conservative opinion states that you should always drive within the speed limit without going over. In cases where there is heavy traffic, do not drive faster than is safe, no matter the speed limit. Safety is the main reason we have speed zones.