Quote From: wyldceltAfter a rash of deaths involving teen drivers in Summer 2004, Colorado passed a bill with further restrictions and requirements on teen drivers. It became effective July 1, 2005. In short teen driver now have to hold their learners permits for 1 year vs 6 months under the old provisions. Teen drivers may not have anyone under 21 years old in their vehicle until after they've had their license for 6 months then they're limited to one passenger. The restrictions have only been in place a few months so its too early to tell how well they're working though this summer passed with only a few deaths, single deaths vs 4, 5 and 6 at a time. Might be worth considering whether your particular states should follow suit to protect your young drivers. 
 
Follow the links below for specific information: 
Over view of requirements 
http://driversed.com/DMV/colorado-GDL.aspx 
New restrictions 
http://www.revenue.state.co.us/mv_dir/wrap.asp?incl=FAQdrli/faqdrli27 
Permit modifications:
http://www.drivereducationinabox.com/colorado/drivers-ed.php 
House Bill 1017 has made several changes in the law relating to the licensing age of minors. These include the following: 
Anyone under age 18 must have their permit for one year before being eligible for their license.
A minor may obtain the permit at age 15 only if the minor is enrolled in an approved driver education course (such as Driver Ed in a Box®).
A minor may obtain a permit at age 16 without driver education.
Regardless of when a minor obtains a permit, the minor must have the permit for 12 months before being eligible for licensing.
 
I don't know about anyone else but I think that 16 year olds shouldn't be driving at all. They should change it so that you have to be at least 18 to get a license for any vehicle.