Driving too fast can lead to the obvious consequences, such as accidents, injuries and/or death. What isn't taken into consideration is driving too fast for current conditions, whether road, weather or traffic. One family lost a child after the father was driving too fast on a slick, icy road. He didn't slow down to account for snow melt freezing as temperatures fell. See link in the Resources section.
A teenager can easily forget the need for managing speed when he gets behind the wheel. If a police officer witnesses him speeding, he will be stopped and ticketed for that violation. The penalty will affect his insurance rates. The Motor Vehicle Division in your state will assess points on your teen's driving record, which, if they get high enough, will get his license suspended. See the link on unsafe driving in the Resources section.
Discuss the consequences of unsafe driving with your teen. Remind him that your insurance rates will go up (let him know that is a definite consequence, not a possibility). Getting a speeding ticket and going to traffic court will be another consequence. Having an accident and getting hurt or hurting another driver or pedestrian is another possibility. He could also face a lawsuit as the result of his actions. Be sure to include any parental consequences which will result.
Insurance companies raise your insurance rates when you add a teen driver to your plan--this is standard practice. If your teen is a male under age 25, your rates will go up noticeably. If your teen is caught speeding, with or without an accident, your rates will go up even higher.
The Centers for Disease Control and Prevention released a 2005 statistic which states that 12 teen drivers die per day in vehicle accidents. Speed was probably a factor in these unnecessary deaths.
Talk to your teen driver and let him know he has to slow down below the posted speed limit if the weather is bad. Wet roads increase stopping distances.