The 1990 Clean Air Act required the implementation of vehicle inspection and maintenance programs in areas that were moderate or worse nonattainment for ozone or carbon monoxide. Over half of the states have such programs in operation. The vehicle inspection programs vary by state. Some of the programs test only emissions, while other programs include inspections for safety features along with the emissions tests.
Drunk driving laws were enacted almost at the same time as the motor vehicle was invented. Over the years the statutes have been changed and strengthened. In 1982, legislation was passed requiring state drunk driving laws to include provisions for a blood-alcohol level of 0.10 as a per se offense and for license suspensions and minimal sentencing restrictions in order for states to continue to qualify for certain federal funding. Legislation passed in 2000 conditioned the availability of federal highway funds upon the states' adoption of a limit of 0.08.
The penalties for driving while impaired tend to be less harsh than the penalties for driving while under the influence or driving while intoxicated. The penalties for driving while impaired do vary depending upon the state. In most cases the offense for a first time offender is considered a misdemeanor.
While a speeding conviction is generally not considered a serious offense, it may have serious implications. If the speed is considered "excessive," (e.g., 30 to 60 miles over the posted speed limit), the conviction will include a fine, imprisonment, and possible suspension of a driver's license. Other criminal actions related to speeding may include "reckless driving" and "racing." Moving violations are either traffic infractions or criminal misdemeanors, and they may necessitate a court appearance.
Most states maintain statutes directing motorists to obey traffic control devices, including green, yellow, and red signals or arrows, lane direction control signals, stop signs, and yield signs. In addition to directing drivers to obey the directions of traffic control devices, the governing statute will explain the appropriate driver responses to traffic control devices. For example, a statute may direct that a driver stop at a clearly marked stop line as the driver approaches a flashing red light used in a traffic control device or with a traffic sign. These statutes also direct driver responses in the event the traffic control signal is out of operation or functioning improperly.