Another factor, when comparing speed, is true average speed over the course of a trip/ride, or moving average speed. Dividing the distance you rode with the total time it took to ride it is a true average speed, which includes stops for signal lights, water, bathroom, etc. Most cyclo computers also offer the option to report this. Most computers also, however, offer a moving average speed, which automatically pauses its calculating when you stop. Depending on your riding environment, there can be a pretty big difference between the reported average speed using these two methods.