engine as the principal way of controlling your speed on downgrades. The braking effect of the engine is greatest when it is near the governed rpms and the transmission is in the lower gears. Save your brakes so you will be able to slow or stop as required by road and traffic conditions. Shift your transmission to a low gear before starting down the grade and use the proper braking techniques. Please read carefully the section on going down long, steep downgrades safely in "Mountain Driving." 

## 2.6.7 – Roadway Work Zones 

Speeding traffic is the number one cause of injury and death in roadway work zones. Observe the posted speed limits at all times when approaching and driving through a work zone. Watch your speedometer, and don’t allow your speed to creep up as you drive through long sections of road construction. Decrease your speed for adverse weather or road conditions. Decrease your speed even further when a worker is close to the roadway. 

1. How far ahead does the manual say you should look? 

2. What are two main things to look for ahead? 

3. What's your most important way to see the sides and rear of your vehicle? 

4. What does "communicating" mean in safe driving? 

5. Where should your reflectors be placed when stopped on a divided highway? 

6. What three things add up to total stopping distance? 

7. If you go twice as fast, will your stopping distance increase by two or four times? 

8. Empty trucks have the best braking. True or False? 

9. What is hydroplaning? 

10. What is "black ice”? 

These questions may be on the test. If you can't answer them all, re-read subsections 2.4, 2.5, and 2.6. 

## Subsections 2.4, 2.5, and 2.6 Test Your Knowledge 

## 2.7 – Managing Space 

To be a safe driver, you need space all around your vehicle. When things go wrong, space gives you time to think and to take action. 

To have space available when something goes wrong, you need to manage space. While this is true for all drivers, it is very important for large vehicles. They take up more space and they require more space for stopping and turning. 

## 2.7.1 – Space Ahead 

Of all the space around your vehicle, it is the area ahead of the vehicle--the space you're driving into - -that is most important. 

The Need for Space Ahead. You need space ahead in case you must suddenly stop. According to accident reports, the vehicle that trucks and buses most often run into is the one in front of them. The most frequent cause is following too closely. Remember, if the vehicle ahead of you is smaller than yours, it can probably stop faster than you can. You may crash if you are following too closely. 

How Much Space?  How much space should you keep in front of you? One good rule says you need at least one second for each 10 feet of vehicle length at speeds below 40 mph. At greater speeds, you must add 1 second for safety. For example, if you are driving a 40-foot vehicle, you should leave 4 seconds between you and the vehicle ahead. In a 60-foot rig, you'll need 6 seconds. Over 40 mph, you'd need 5 seconds for a 40-foot vehicle and 7 seconds for a 60-foot vehicle. See Figure 2.12. 

To know how much space you have, wait until the vehicle ahead passes a shadow on the road, a pavement marking, or some other clear landmark. Then count off the seconds like this: "one thousand- and-one, one thousand-and-two" and so on, until you reach the same spot. Compare your count with the rule of one second for every ten feet of length. 

