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Drunk Driving Defense Attorneys

DUI Enforcement by the California Highway Patrol

The California Highway Patrol (CHP) conducts more DUI arrests than any other police agency in the state. The CHP maintains primary authority over all state routes, U.S. highways and interstate highways. Traffic and DUI enforcement are the major part of what CHP officers do.

Because CHP officers spend so much of their time on DUI enforcement, they tend to be better trained and more experienced when it comes to DUI investigations.

However, contrary to popular belief, this does not translate to a better ability to discern whether and to what extent particular DUI suspects are impaired. Studies have shown that even the most experienced DUI officers are no better than bartenders or even social drinkers when it comes to judging peoples' levels of intoxication.

The California Highway Patrol DUI Enforcement Manual

The California Highway Patrol's DUI Enforcement Manual is meant to serve as a training material and an ongoing reference for CHP officers. Among other things, it outlines what driving patterns may indicate that a driver is under the influence, how to administer the field sobriety tests, and how to administer blood and breath tests to measure BAC.

We encourage everyone arrested for DUI by the CHP to read the DUI Manual as a means of educating themselves about the DUI investigation process. Quite often, we find, things are not done "by the book." Failure to follow the appropriate procedures is one of the many things that can derail a DUI prosecution at the DMV and in court.

The CHP DUI Enforcement Manual (PDF)

Facts About The CHP:

  • The CHP is a state police force with jurisdiction over California and Federal highways.
  • With nearly 7000 sworn police officers, the CHP is the nation's largest state police force.
  • In 1995, the CHP merged with the California State Police, which was then a separate agency. The merger expanded the duties of the CHP to include protecting California office buildings, protecting California state properties and protecting elected California officials.

Southern California DUI Defense


DUI cases are rarely hopeless. DUI convictions are almost never inevitable. Clients retain our California DUI defense attorneys for one reason: they want to fight the case. And win.

Contact Us For Help

The police arrested you for DUI. You gave a blood or a breath sample. The DUI officer confiscated you drivers license. The police released you with a notice to appear in court in a few weeks. Where do you go from here? Our lawyers are here to guide you step by step.