Speeding is a leading cause of motor vehicle accidents. Drivers typically speed because they believe they will arrive at their destination quicker. A common misconception that many drivers have is that driving 10 km/h over the posted speed limit is low risk and will cut down on their commute time. Anecdotal evidence also suggests that law enforcement officers will not pull you over if you are speeding between 5 to 9 km/h over the posted speed limit. In reality, if you are driving even 1 km/h over the posted speed limit and a police officer with a speed gun clocks you, they are well within their rights to issue you a speeding ticket. However likely or unlikely this is to happen in real life is debatable, and not the subject of this article.

Appropriate speed limits are determined by taking into account a variety of factors, including road design, volume of traffic, as well as the likelihood of encountering pedestrians in the area. Speed limits are set for ideal road conditions, so if the roads are wet or icy and visibility is poor, the posted speed limit will be too fast. These are not arbitrarily imposed limits and they are enforced for public safety. By following the posted speed limit, you decrease your odds of being involved in a motor vehicle collision and potentially injuring yourself and another person.

Will I Save Time on My Daily Commute?

At lower speeds, typically within city limits, traveling between 5-10 km/h over the speed limit will shave off a couple of minutes of travel time at most. During rush hour, any hypothetical time savings are negated by a driver’s inability maintain a constant speed when traveling with the flow of traffic. Every time you stop for a red light, or with the flow of traffic, it will take you time to accelerate back up to speed again. The timing of a traffic light cycle is also specifically engineered to decrease traffic congestion and safely control the flow of traffic. It is essentially impossible to accurately time when to “speed up” in order to avoid stopping at a red light, especially when most traffic light cycles vary throughout the day and according to the number of drivers on the road. Any minor gains you make by speeding through an intersection are likely to be lost over the course of your commute through future traffic light cycles.

Hypothetical Time Savings

In the city, on a road where the speed limit is 60 km/h, if you were to travel 30 km under perfect conditions (ideal roads, no traffic lights), it would take you approximately 30 minutes to arrive at your destination. If you travel at 65 km/h, an increase of 5 km/h over the speed limit, it would take you 27.7 minutes to travel the same distance of 30 km, saving you only 2.3 minutes of travel time. Your likelihood of getting a speeding ticket may be debatable, but studies have shown that you have doubled your risk of being involved in a motor vehicle accident. Assuming you did receive a speeding ticket for traveling 5km/h over the speed limit, it would cost roughly $90 to cut 2.3 minutes off your travel time.

The above scenario was calculated under absolute perfect driving conditions that in no way reflect the reality of the typical daily commute. When you are travelling at 10 km/h over the posted speed limit, studies have shown that your chances of being involved in a collision quadruple. An abrupt stop, whether to avoid another vehicle or stop for a pedestrian, while driving 60 km/h on a road where the speed limit is 50 km/h will increase your stopping distance by 10.4 meters when compared to a similar stop at 50 km/h. This is roughly two car lengths in distance, which could mean the difference between life and death for a pedestrian.

What About Highway Driving?

If you were traveling on a straight road with a speed limit of 90 km/h, and you exceeded this speed limit by the anecdotally “acceptable” 10 km/h, you still would not make any significant time savings. This is because the faster you are traveling, the more you have to exceed the speed limit to achieve a proportionate increase in speed. To expand on this, if the speed limit is 50 km/h and you are traveling 60 km/h, you are traveling 20% faster than the posted speed limit. If the speed limit is 90 km/h and you are traveling 100 km/h, you are only traveling roughly 11% faster than the posted speed limit. In order to make any significant time gains, you would need to be traveling very fast over a greater distance. At this stage you would be far more likely to be involved in a fatal collision or get pulled over by a law enforcement officer.

On a 200 km trip on a stretch of highway where the speed limit is 100 km/h, it would take you roughly 2 hours to arrive at your destination under ideal conditions. Speeding would yield the following approximate time savings, and result in the following approximate speeding ticket fines in Alberta:

Distance Speed Time Time Saved Potential Fines
200 km 120 km/h 1.67 hours (100 minutes) 20 minutes $140 – $239
200 km 135 km 1.48 hours (89 minutes) 31 minutes $253 – $474
200 km 155 km/h 1.29 hours (77.4 minutes) 42.6 minutes $650 – $2000, plus the potential for a driver’s license suspension



The faster your car is traveling, the more force you will transfer over if you do collide with another object or vehicle, thereby putting yourself and another person at risk of severe injury or death. Driving over the speed limit increases the required braking distance and stopping time in case a vehicle in front of you comes to an abrupt stop, or a pedestrian or cyclist crosses your path. A large number of our clients were rear-ended, usually when traffic abruptly came to a stop or while waiting at a red light. The resulting injuries are often very significant and life-altering.

In conclusion, one of the most effective ways to prevent being involved in a motor vehicle accident is to slow down and abide by the posted speed limit. By speeding within city limits, potentially cutting down a couple minutes of travel time, you are significantly increasing your risk of being involved in a collision and injuring another person. In addition, your vehicle is subjected to greater wear and tear with rapid acceleration and deceleration. Your vehicle is also less fuel efficient at greater speeds. For example, increasing your speed from 90 km/h to 120 km/h can lower fuel efficiency by as much as 20%. The end result will cost you more money in fuel, car maintenance, insurance premium increases, vehicle repair deductibles, and speeding ticket fines. It’s simply not worth it, and you will not arrive at your destination any quicker.

Article courtesy of Conway Injury Law.