For most of this country’s life, matters dealing with local public safety, including DUI and traffic laws, have been the responsibility of state government. The one notable exception has been the rules of the road governing traffic on the Interstate highway system, whose funding comes primarily from the federal government, and of course the Interstate highway systems crosses the boundaries of all the states.
Beginning in 1984 and continuing to this day, that changed. While beyond the Commercial Driver’s License CDL law Congress has not explicitly injected itself into traffic laws, it has done so indirectly. When it wants states to do something, Congress uses the coercive power of the purse: if a state does not pass a law Congress believes it should, Congress withholds federal highway money.
Prior to 1984, the age at which a person could purchase, or possess, or consume alcohol varied among the states. In Illinois, the age for beer and wine was 19, and it was 21 for distilled alcohol. In Iowa, the age for all alcoholic beverages was 18.
Today, the drinking age in Illinois is 21. 235 ILCS 5/6-16 It is the same in all 50 states. No state wants to forfeit federal highway funds.
At one time, each state was free to set its own legal limit for blood alcohol content, or to have no limit at all. In Illinois, the limit was initially 15, later lowered to .10. Today, it is .08. (625 ILCS 5/11-501(a)(1)), as it is in all 50 states. The reason for this is, that’s how the federal government wants it to be.
The federal government has gotten involved more directly pertaining to CDLS It has been accepted that because over-the-road truckers cross state boundaries, a uniform set of laws benefits both the motoring public and the trucking industry. While the federal government has not written a specific CDL law, it has set forth guidelines that all states are required to follow at the risk of losing their ability to issue CDLS if they fail to do so. Commercial Motor Vehicle Safety Act of 1986 (CMVSA) (Title XII of Pub. Law 99-570) [49 U.S.C. § 2701 et seq.]