2005 Model Commercial Driver’s License Manual transmission and also lead to loss of all engine  braking effect.  With older trucks, a rule for choosing gears is to  use the same gear going down a hill that you would  need to climb the hill. However, new trucks have  low friction parts and streamlined shapes for fuel  economy. They may also have more powerful  engines. This means they can go up hills in higher  gears and have less friction and air drag to hold  them back going down hills. For that reason, drivers  of modern trucks may have to use lower gears  going down a hill than would be required to go up  the hill. You should know what is right for your  vehicle.  as necessary until you have reached the end of the  downgrade.  Escape ramps have been built on many steep  mountain downgrades. Escape ramps are made to  stop runaway vehicles safely without injuring  drivers and passengers. Escape ramps use a long  bed of loose, soft material to slow a runaway  vehicle, sometimes in combination with an upgrade. Know escape ramp locations on your route. Signs  show drivers where ramp are located. Escape  ramps save lives, equipment and cargo.  Brakes are designed so brake shoes or pads rub  against the brake drum or disks to slow the vehicle.  Braking creates heat, but brakes are designed to  take a lot of heat. However, brakes can fade or fail  from excessive heat caused by using them too  much and not relying on the engine braking effect.  Brake fade is also affected by adjustment. To safely  control a vehicle, every brake must do its share of  the work. Brakes out of adjustment will stop doing  their share before those that are in adjustment. The  other brakes can then overheat and fade, and there  will not be enough braking available to control the  vehicle. Brakes can get out of adjustment quickly,  especially when they are used a lot; also, brake  linings wear faster when they are hot. Therefore,  brake adjustment must be checked frequently.  Remember.  The use of brakes on a long and/or  steep downgrade is only a supplement to the  braking effect of the engine. Once the vehicle is in  the proper low gear, the following are the proper  braking techniques:  For example, if your "safe" speed is 40 mph, you  would not apply the brakes until your speed  reaches 40 mph. You now apply the brakes hard  enough to gradually reduce your speed to 35 mph  and then release the brakes. Repeat this as often  Stopping is not always the safest thing to do in an  emergency. When you don't have enough room to  stop, you may have to steer away from what's  ahead. Remember, you can almost always turn to  miss an obstacle more quickly than you can stop.  Traffic emergencies occur when two vehicles are  about to collide. Vehicle emergencies occur when  tires, brakes, or other critical parts fail. Following  the safety practices in this manual can help prevent  emergencies. But if an emergency does happen,  your chances of avoiding a crash depend upon how  well you take action. Actions you can take are  discussed below.  These questions may be on the test. If you can’t  answer them all, re-read subsections 2.15 and  2.16. 2.16.3 – Brake Fading or Failure  2.16.4 – Proper Braking Technique  2.17.1 – Steering to Avoid a Crash  2.17 – Driving Emergencies  Subsections 2.15 and 2.16  Test Your Knowledge  • Apply the brakes just hard enough to feel a  definite slowdown.  • When your speed has been reduced to  approximately five mph below your "safe" speed,  release the brakes. (This brake application  should last for about three seconds.)  • When your speed has increased to your "safe"  speed, repeat steps 1 and 2.  1.  What factors determine your selection of a  "safe" speed when going down a long, steep  downgrade?  2.  Why should you be in the proper gear before  starting down a hill?  3.  Describe the proper braking technique when  going down a long, steep downgrade.  4.  What type of vehicles can get stuck on a  railroad-highway crossing?  5.  How long does it take for a typical tractor-trailer  unit to clear a double track?  Section 2 – Driving Safely Page 2-30 Page 2-30  Section 2 – Driving Safely 