Chapter 4 — Your Driving 51 Even with ideal conditions, if you are traveling 55 miles per hour your vehicle  requires approximately 211 feet to stop completely. Driving at a high speed is dangerous because each additional mile traveled  per hour reduces the driver’s ability to control the vehicle. Speed also increases  the likelihood that a crash will result in serious injury or death. On the other  hand, driving below the posted speed limit can also be dangerous. If you must  drive slower, you should still observe the posted minimum speed limit. At  places where it is unsafe to pass, the slow driver forces other drivers to creep  along behind or take unnecessary risks while trying to pass. Very slow driving  is especially dangerous just after you have passed the crest of a hill or rounded  a curve. Faster-moving vehicles can crash into the slower vehicle before they  can slow down. For this reason, watch for slow-moving vehicles such as heavy  trucks or farm vehicles. If traffic is collecting behind you, it is wise to pull over  to the side of the road, stop and allow the vehicles to pass. The most important rules about speed are: Conditions often change as you drive. You will drive through different areas  such as open country, residential communities and school zones. Watch for  changing conditions and adjust your speed accordingly. Unless otherwise posted, the speed limit is 35 mph in cities and towns. Special  speed limits may be posted for special areas. To be a safe driver, you must often  drive slower than the posted limit, but you should not drive faster. The best way to handle a curve: In cities and towns  35 For school buses  45 For school activity buses  55 Outside cities and towns  For interstates  70 Maximum Speed Limits Rounding a Curve • Never drive faster than the posted speed limit or at a speed that is  unreasonable or unwise given the existing conditions. • Allow a safe distance between you and the vehicle in front of you (the “two- second rule”). • The faster you are moving, the farther ahead you must be able to see to allow  enough distance for stopping. Studies show that the vehicle moving at a speed considerably below the posted limit is much more likely to cause or be involved in a crash than the vehicle moving at a normal speed. 1. Slow down before you enter the curve so that you will not need to brake  while you are in the curve; 2. Gradually increase your speed to maintain the traction necessary for good  control of the vehicle as you round the curve;