With El Niño “too big to fail,” and the Orange County area expected to be among the hardest hit parts of California when rains begin to pour, now is the time to prepare. The good news is that winter’s heaviest storms aren’t expected to arrive until January, providing motorists a window of opportunity to ready their vehicles. But when those storms do get here, road conditions are expected to be “treacherous,” said Dave Skaien, auto repair program manager for the Automobile Club of Southern California. “Motorists should expect lots of rain and water gathering in places that it hasn’t gathered in years.”

Following are the top safety issues drivers should address now:

1. Underinflated tires

There are two major safety issues involving tires: underinflation and tread wear. Underinflated tires do not behave predictably or consistently, Skaien said. “If tires aren’t inflated correctly, they could impact your ability to brake efficiently and keep control of your vehicle. It will increase braking distances, which puts you at risk for collisions.” Almost 85 percent of cars on U.S. roads have at least one underinflated tire, according to the Rubber Manufacturers Association.

AAA recommendation: Check tire pressure at least once a month. Remind yourself by scheduling it on your calendar. Check tires when they are cold – before you drive – because pressure increases when tires are warm. Buy a tire pressure gauge and keep it in your glove compartment.

Cost: $5 for tire pressure gauge; $1 for pressurized air at a service station.

2. Worn tires

Tires with inadequate tread can slip on wet surfaces and cause skidding. While a tread depth of 1/16th of an inch is adequate in dry conditions, drivers need at least 3/16th of an inch when roadways are wet, Skaien said. “What a tread does is move water out of the way of the tires so they can still touch the ground. When those grooves get thin, tires can’t move the water through the grooves so it sits between the tire and the road and causes hydroplaning, eliminating your ability to steer and brake.”

AAA recommendation: Use a penny to measure tread depth. Stick the penny into the tire’s groove upside down. If you can see Abraham Lincoln’s hair, the tire is worn out. If Lincoln’s head is cut off, there is plenty of tread remaining.

Cost: Varies by make and model but averages $500 to $2,000 for a set of four tires.

3. Weak brakes

Brakes are a vehicle’s most important safety feature. On wet roads, it takes longer to stop a vehicle. If the brake light is showing up on your dashboard or you have noticed that the brakes feel soft, be sure to have your brakes checked by a trusted mechanic.

AAA recommendation: Have brakes inspected with each service visit.

Cost: Varies by make and model but averages $400 to $1,000 to replace both the front and rear brakes.

4. Broken or fogged lights

Rain reduces visibility, for drivers as well as surrounding vehicles. Be sure all lights are properly functioning so you can see what’s ahead of you and so other vehicles know you are there. Cloudy headlight lenses dramatically decrease light output at night, reducing your ability to see objects and react to them in time.

AAA recommendation: When parking in front of a store at night, check whether lights are working by using the reflection of the store’s glass windows. When parked facing a window, check headlights, high beams and front turn signals. To check back lights, park your car with its back facing the glass, and use the rearview mirror to check tail lights, brake lights and turn signals.

Cost: Varies by make and model but restoring foggy headlights averages $50 to $100.

5. Wiper blades and washer fluid

“A lot of people don’t think about wiper blades as a safety feature, but they absolutely are,” Skaien said. “An obstructed windshield is not safe, especially in the rain, and especially at night.” If your wipers are streaking or skipping, they are worn out.

AAA recommendation: Check wiper blades monthly. Be sure windshield washer solvent reservoir is full with washer fluid, not water. Washer fluid is formulated to cut through dirt and oil that may be on the windshield glass.

Cost: $10 to $25 per blade.

6. Old or weak batteries

Cold and wet weather breaks down car batteries and can increase the rate at which battery terminals corrode. The result: not enough electrical power to start the car.

AAA recommendation: Once a battery is three years old, it should be checked each time the car is serviced. Most batteries last five years. Do not wait for a battery to die before replacing it.

Cost: Varies by make and model but is generally $150 to $300, including installation.

Contact the writer: scarpenter@ocregister.com