2.6.6 – Speed on Downgrades Your vehicle's speed will increase on downgrades because of gravity. Your most important objective is to select and maintain a speed that is not too fast for the Total weight of the vehicle and cargo. Length of the grade. Steepness of the grade. Road conditions. Weather. If a speed limit is posted, or there is a sign indicating "Maximum Safe Speed" never exceed the speed shown. Also, look for and heed warning signs indicating the length and steepness of the grade. You must use the braking effect of the 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 byroad 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 ongoing down long, steep downgrades safely in "Mountain Driving"