If you knew there was a high chance of pouring rain today, you'd probably close your windows, right?

The same preparation can apply to car insurance for teens: Teen drivers have the highest chance for car accidents, so buying ample auto insurance is wise. If your teen driver causes more damage than your insurance will pay for, you could be sued.

The rate of fatal crashes for drivers ages 16 to 19 is three times the rate for 20-year-olds. The riskiest driving ages are 16 and 17, according to the Insurance Institute for Highway Safety.

Here's a look at car insurance types to consider when you have a teen driver.

Overview: Car insurance for teen drivers

Liability insurance Pays for the damage and injuries you cause others. Because teens have the highest chance of causing accidents, it's smart to have more than the minimum liability insurance required by your state. Consider at least 100/300/50, meaning:
  • $100,000 for injuries per person
  • $300,000 for injuries per accident
  • $50,000 for property damage per accident
Collision and comprehensive insurance These pay for damages to your own car. They are typically sold as a package. Consider the chances of your teen crashing into another car, backing into a pole or hitting a sign. That's why you want collision and comprehensive insurance. (If you have a car loan your lender probably already requires these.)
Umbrella insurance An umbrella insurance policy adds an extra layer of liability insurance to your auto and homeowners insurance. It's a good way to add a lot of extra insurance cheaply. You can get a $1 million umbrella policy for about $150 to $300 a year, according to the Insurance Information Institute.

Your state may require other insurance types such as uninsured motorist coverage or personal injury protection (PIP).

The cost of adding a teen driver

There's no way to avoid a rate increase when you have a teen driver, and you may not get cheap car insurance until the teen is over age 25 and has a good record. Adding a teen driver to a parent's policy can increase rates from 20% to 180% or higher, depending on the state, according to Trusted Choice, a group for independent agents.

Ways to get cheap car insurance for teens

Add the teen to the parents' insurance policy instead of putting the teen on a separate policy. This way the rate increase for the teen driver can be offset by discounts you already have on the policy. And if you're buying a car for the teen, you can also get a multi-vehicle discount. Geico offers a "Family Pricing Program" that lets you move your teen to their own policy while keeping the same rates.

Shop around: Compare car insurance by getting quotes from multiple companies. This offers the chance to save hundreds of dollars because rates vary so much among insurance companies.

Ask your insurance agent to review possible discounts. Make sure you're getting all the car insurance discounts possible, such as a good student discount if your teen maintains certain grades.

If you're buying your teen a car, buy one that's safe and cheap to insure. If you're considering a number of cars, ask your insurance agent to give you quotes for each. That way you won't have surprises after you buy a car. The Insurance Institute for Highway Safety has tips for choosing a vehicle for a teen.

If the teen goes away to college without a car, tell your insurer. Many offer price breaks for a teen away at college because they'll won't be driving the car regularly.

Tips for parents of teen drivers

  • Know your state's graduated licensing laws: These laws lower the risk of teen drivers by introducing them the road and driving others in stages. See graduated licensing laws at the Governor's Highway Safety Association.
  • Make a written agreement about driving expectations and consequences. The CDC has a free parent-teen driving agreement that can be downloaded.
  • Ensure your teen isn't texting while driving. Drivers under age 21 are 15% more likely to use their phone on trips than those over 21, according to EverQuote's Safe Driving Report. There are free apps that block texts during driving. Also, Apple's iOS 11 comes with a "Do Not Disturb" feature that automatically blocks texts when your iPhone senses you're driving. Android has a similar function on newer phones.
  • Ask your insurance agent when the teen needs to be added to the policy. Some companies will want you to add the teen when they get a license. Others will base the timing on the age of the teen, according to Trusted Choice.