Final answer:
You may receive a ticket for speeding even if driving at or below the posted limit if conditions warrant a slower speed or if your driving is unsafe for the current conditions. The de facto speed limit is the threshold at which police enforce speeding, which can differ from the posted limit. Drivers are always responsible for maintaining safe speeds relative to various conditions.
Step-by-step explanation:
Under certain conditions, you may receive a ticket for speeding, even if you are driving at or less than the posted speed limit. For example, if the conditions are such that driving at the speed limit is unsafe (during a heavy storm, in a school zone when children are present, or in reduced visibility), authorities can issue tickets for not adjusting speed appropriately. Speed limits act as a guide under normal conditions, but drivers are expected to use discretion and reduce speed when necessary. Moreover, the speedometer calibration may be off, granting drivers a slight margin for error, but excessive reliance on this leeway can lead to a ticket. The de facto speed limit may differ from the de jure speed limit, which is the officially posted speed. The de facto limit refers to the threshold above the official limit at which police officers will typically issue speeding tickets, recognizing minor variances in speedometer accuracy and enforcement practices. In areas where safety is a high priority, such as near schools or in construction zones, authorities may have a zero-tolerance policy for speeding. In physics terms, the scenario of getting a ticket due to long skid marks, as described in the question, indicates that the driver was going at a speed where their stopping distance was too great, suggesting they were likely exceeding the safe driving speed for the conditions, thus warranting a ticket for speeding. Ultimately, it is a driver's responsibility to maintain a safe driving speed relative to the road, traffic, and weather conditions, regardless of posted speed limits.