With the Florida CDL Driver Handbook, you can study up on the worries that particularly relate come earning her CDL endorsement.

You are watching: A truck will take how much longer to stop on a wet road than a car?


Table of Contents

2. Driving Safely

Driving too quick is a significant cause of deadly crashes. Girlfriend must readjust your speed relying on driving conditions. These include traction, curves, visibility, traffic and hills.

2.6.1 - avoiding Distance


*
Figure 2-11

Perception distance + Reaction distance + Braking distance =Total Braking Distance

Perception Distance. This is the street your car travels from the time your eyes view a hazard until your brain recognizes it. The late time because that an alarm driver is around 3/4 second. At 55 mph, you take trip 60 feet in 3/4 2nd or about 81 feet every second.

Reaction Distance. The distance traveled from the time your mind tells your foot to relocate from the accelerator until your foot is actually pushing the brake pedal. The average driver has actually a reaction time that 3/4 second. This account for secondary 60 feet travel at 55 mph.

Braking Distance. The distance it takes come stop when the brakes are put on. In ~ 55 mph on dried pavement with good brakes, it have the right to take a hefty vehicle about 390 feet come stop. The takes around 4 1/2 seconds.

Total Braking Distance. in ~ 55 mph, it will take about six secs to stop and your auto will travel around 450 feet.

The quicker you drive, the better the impact or striking power of your vehicle. When you dual your speed from 20 come 40 mph the affect is 4 time greater. The braking street is also 4 time longer. Triple the rate from 20 to 60 mph and the impact and braking street is 9 times greater. At 60 mph, your avoiding distance is higher than the length of a football field. Rise the speed to 80 mph and the impact and braking distance are 16 times better than in ~ 20 mph. High speeds substantially increase the severity that crashes and also stopping distances. By slow down, you can reduce braking distance.. See figure 2.11

The result of car Weight on protecting against Distance. The more heavier the vehicle, the much more work the brakes need to do to avoid it, and also the more heat lock absorb. Yet the brakes, tires, springs, and shock absorbers on hefty vehicles room designed to work ideal when the car is totally loaded. Empty trucks require better stopping distances due to the fact that an empty automobile has much less traction.

2.6.2 - corresponding Speed come the road Surface

You can"t steer or brake a auto unless you have traction. Traction is friction between the tires and also the road. There room some road problems that minimize traction and call for lower speeds.

Slippery Surfaces. It will certainly take much longer to stop, and it will certainly be more tough to turn without skidding, once the roadway is slippery. Wet roads can dual stopping distance. You need to drive slower to be able to stop in the exact same distance together on a dried road. Mitigate speed by around one-third (e.g., slow from 55 to about 35 mph) top top a wet road. On packed snow, minimize speed by a half, or more. If the surface is icy, reduce speed come a crawl and stop steering as shortly as you have the right to safely carry out so.

Identifying Slippery Surfaces. occasionally it"s hard to know if the road is slippery. Below are some indications of slippery roads:

Shaded Areas. Shady parts of the road will remain icy and also slippery long after open areas have melted. Bridges. As soon as the temperature drops, bridges will freeze before the roadway will. Be especially cautious when the temperature is close come 32 degrees Fahrenheit. melting Ice. Slight melting will make ice cream wet. Wet ice is much much more slippery than ice the is not wet. black color Ice. Black color ice is a slim layer the is clear enough that you deserve to see the road underneath it. It makes the roadway look wet. Any kind of time the temperature is listed below freezing and the roadway looks wet, watch out for black ice. car Icing. An easy method to inspect for ice cream is to open the home window and feel the former of the mirror, winter support, or antenna. If there"s ice cream on these, the road surface is probably starting to ice cream up. just After Rain Begins. Best after it starts come rain, the water mixes through oil left ~ above the road by vehicles. This renders the road really slippery. If the rain continues, it will certainly wash the oil away. Hydroplaning. In some weather, water or slush collection on the road. As soon as this happens, your vehicle can hydroplane. It"s prefer water skiing--the tires shed their contact with the road and have tiny or no traction. You might not be able to steer or brake. You can regain regulate by publication the accelerator and pushing in the clutch. This will sluggish your vehicle and also let the wheels turn freely. If the automobile is hydroplaning, execute not use the brakes to sluggish down. If the drive wheels begin to skid, press in the clutch come let them rotate freely.

It does no take a most water to reason hydroplaning. Hydroplaning can take place at speeds as low as 30 mph if over there is a many water. Hydroplaning is more likely if tire push is low, or the tread is worn. (The grooves in a tire lug away the water; if they aren"t deep, they don"t job-related well.)

Road surfaces where water can collect have the right to create problems that reason a auto to hydroplane. Watch for clear reflections, tires splashes, and raindrops ~ above the road. These are indications of was standing water.

2.6.3 - Speed and also Curves

Drivers must adjust their speed for curves in the road. If you take a curve also fast, 2 things deserve to happen. The tires deserve to lose their traction and continue straight ahead, so you skid off the road. Or, the tires might keep your traction and also the auto rolls over. Test have presented that trucks with a high center of gravity deserve to roll over at the posted rate limit because that a curve.

Slow come a for sure speed prior to you get in a curve. Braking in a curve is dangerous since it is much easier to lock the wheels and also cause a skid. Slow down together needed. Don"t ever before exceed the posted speed limit for the curve. It is in in a equipment that will let girlfriend accelerate slightly in the curve. This will help you keep control.

2.6.4 - Speed and Distance Ahead

You should always be able to protect against within the street you can see ahead. Fog, rain, or other conditions may call for that you slow down to be able to stop in the distance you have the right to see. At night, friend can"t view as much with low beams together you can with high beams. When you need to use low beams, sluggish down.

2.6.5 - Speed and also Traffic Flow

When you"re control in heavy traffic, the safest rate is the speed of other vehicles. Vehicles walking the exact same direction at the same speed space not likely to run into one another. In plenty of states, speed limits are reduced for trucks and buses 보다 for cars. It have the right to vary as lot as 15 mph. Use extra caution once you readjust lanes or pass on this roadways. Drive at the rate of the traffic, if you can without going in ~ an illegal or unsafe speed. Store a safe complying with distance.

The main reason vehicle drivers exceed speed borders is to save time. But, anyone trying come drive faster than the rate of website traffic will not be able to save much time. The risks associated are no worth it. If girlfriend go much faster than the speed of various other traffic, you"ll need to keep passing various other vehicles. This increases the opportunity of a crash, and also it is more tiring. Tiredness increases the chance of a crash. Going through the flow of traffic is safer and also easier.

2.6.6 - rate on Downgrades

Your vehicle"s rate will boost on downgrades because of gravity. Your most vital objective is come select and maintain a speed that is no too fast for the:

complete weight that the vehicle and also cargo. size of the grade. Steepness the the grade. road conditions. Weather.

See more: Here'S Why Are Asian Restaurants Closed On Mondays ? Why Are Chinese Restaurants Closed On Mondays

If a speed limit is posted, or there is a authorize indicating "Maximum for sure Speed," never ever exceed the speed shown. Also, look for and also heed warning indications indicating the length and also steepness the the grade. You must use the braking result of the engine as the principal way of regulating your rate on downgrades. The braking result of the engine is biggest when the is close to the governed rpms and the infection is in the lower gears. Save your brakes so you will have the ability to slow or protect against as compelled by road and also traffic conditions. Shift your transmission to a low equipment before beginning down the grade and also use the ideal braking techniques. Please read closely the ar on going down long, steep downgrades for sure in "Mountain Driving."

2.6.7 - Roadway work Zones

Speeding website traffic is the number one cause of injury and death in roadway work zones. Observe the post speed limits at every times once approaching and driving through a occupational zone. Watch her speedometer, and also don"t enable your rate to creep up together you journey through long sections of roadway construction. To decrease your rate for adverse weather or road conditions. Decrease her speed also further as soon as a worker is close come the roadway.