Final answer:
The unlawful speed limit on streets of cities and towns is generally above 31 miles per hour, with some leeway for slight exceedances. Adhering strictly to the posted speed limit, like the driver in front of Peter, is within legal rights.
Step-by-step explanation:
It is unlawful to travel more than 31 miles per hour (50 kilometers per hour) on streets of cities and towns, as this is a typical speed limit for a residential area. While there may be some leeway for slight speed overages, such as driving at 31 miles per hour in a 30 mph zone, exceeding these limits by a significant amount can result in a traffic ticket. In the context of the story provided, Peter was impatient with a driver adhering to the minimum speed, though legally, the other driver was within his rights to travel at that speed.