The Brief Essentials of Californian Driving

If you read nothing else in this guide, you ought to at least know the following:

• In an emergency, dial 9-1-1 for police, fire, or emergency medical services.
  
  

• Your out-of-state or foreign driver's license is normally valid for driving in California if it's valid in the country or state of issue, but you need a Californian driver's license if you're resident in California for more than ten days (this does not apply to people legitimately traveling in California for more than 10 days who don't need a California license unless they end up settling here).
  
  

• The default urban speed limit is 25 miles per hour (M.P.H. -- i.e. 40 K.P.H.); freeway speed limits are usually 55, 65, or 70 M.P.H. (approximately 90, 100, and 110 K.P.H. respectively).
  
  

• Most Californians don't by and large bother with turn signals when turning or changing lanes. This is both dangerous and illegal, but very widespread.
  
  

• Californian drivers usually ignore lane discipline and drive in whatever lane they feel like, regardless of speed. Luckily it's usually legal to pass ("overtake") in a slower lane.
  
  

• Red lights ("stop lights") and stop signs are regarded as purely advisory by a significant proportion of drivers, especially late at night. This is highly illegal and dangerous.
  
  

• Red-colored curbs mean "don't park here under any circumstance". Blue ones mean "only park here if you're disabled and have an approved permit to park in disabled spaces". Green-colored curbs usually have a short time limit (15 to 30 minutes) on parking.
  
  

• It's generally legal to turn right on a red light as long as you stop first, there's no conflicting traffic, and no sign saying "No Right Turn On Red". It's almost never legal to turn left (i.e. against oncoming traffic) against a red light.
  
  

• It's generally legal to make a U-turn at an intersection, as long as it's safe and there's no sign prohibiting U-turns.
  
  

• At an intersection with stop signs on each entry to the intersection (usually called a "four-way stop junction"), the first person to the intersection gets to go first, with the others taking turns according to when they got there. If two or more cars get there at the same time, the ordering is clockwise.
  
  

• You and all your passengers must wear seat belts, and children must be secured in an appropriate child passenger restraint (safety seat or booster seat) until they are at least 6 years old or weigh at least 60 pounds.
  
  

• You can be charged for driving under the influence (DUI) if you are found to have a blood alcohol percentage of 0.08% or greater. This is a serious criminal offence in California.
  
  

• Motorcycle riders must wear helmets at all times while riding.
  
  

• The sign that you're being pulled over by the police is usually a red light shining at you from the police car (in addition to the other flashing lights).
  
  

• You usually have to pay the cashier before you pump gas (petrol) into your car at a gas station if you're paying cash. Virtually all gas stations take the normal credit cards (Visa, Mastercard at least) and most have automatic pay-at-the-pump facilities.
  
  

• Don't even think of smoking in restaurants, hotels, offices, bars, and public spaces, at least without first asking. Smoking is illegal or banned pretty much everywhere now in California except private homes and other non-commercial private spaces.