All states have laws that prohibit drivers from following another vehicle too closely. Of course, most people know this as "tailgating." Not only is tailgating annoying to other drivers, but it's an infraction or a misdemeanor, depending on what state you live in.
Here are the basics about how following-too-closely offenses are defined, the penalties for a violation, and some possible defenses to a tailgating ticket.
Specific definitions of tailgating vary somewhat by state. But in most states, you can be cited for a following-too-closely violation for:
Both types of following too closely have the purpose of preventing accidents. The first seeks to prevent rear-end accidents and the second is to prevent head-on accidents that could result from when a vehicle passes another vehicle and subsequently doesn't have enough space to merge back in.
Most tailgating laws contain exceptions for situations where a motorcade is driving together to a certain location, such as for a funeral procession and the like. Also, tailgating laws typically provide flexibility by requiring leaving space in front of your vehicle whenever "conditions permit." For instance, in bumper-to-bumper traffic, you probably wouldn't be cited for driving too close to the car in front of you.
Depending on the law of the state where you receive the ticket and other circumstances, following too closely is normally a traffic infraction or a misdemeanor. Typically, drivers who are convicted are looking at having to pay a fine of about $100 to $500 or so and having demerit points assessed to their driving record. And in some states, a tailgating ticket can also lead to jail time, though it probably isn't common.
Fight a tailgating ticket can be tough. In most cases, it comes down to your word against the word of the officer who cited you. However, if you do decide to contest your ticket, you'll want to know the factors that are relevant.
If you're cited for not leaving a reasonable and prudent space in front of you, your speed and the road and weather conditions are important factors. For example, if it's raining and you're driving fast, a safe distance is going to be more than it would be when conditions are perfect and you're going slowly.
With citations for not leaving enough space for another vehicle to pass and merge, the actual distance your car and the car in front of you is the main factor.
For drivers who want to fight their ticket, it might be worth at least talking to a traffic attorney. Attorneys with experience handling these types of cases will likely have the best idea of how best to handle a given situation.