Telehandlers are machinery which are designed to work in rough environment, however, that doesn't mean that they could be driven without any regard for the environment. These types of machinery have a much greater risk of load loss or tipping over when they are traveling on slopes.
When traveling on a slope, make sure that you move slowly with the machinery while also keeping the load low. Downshift to 4WD and a lower gear, prior to getting on the slope. Utilizing the engine brake will actually help to control the speed of the telehandlers. Try to avoid turning on a slope if possible. If you need to make the turn, use extreme caution and take it as wide as possible.
Under any circumstances, avoid driving across excessively steep slopes. Ascend and descend slopes with the telehandler's heavy end pointing up the incline. Even when there is no cargo on the forks, the counterweighted rear of the machinery is fairly heavy; hence, it can be required to drive in reverse up slopes. Once the telehandler is carrying a cargo, the front of the unit becomes the heavy end, and you would be able to back the machine down the slopes.
On a mixed jobsite, operator training is really important. The coordinated steering machines, along with the rear-pivot machines usually operate on the same jobsite where everybody is allowed to operate all of the machines. In this instance, a person who is used to using a coordinated steer machinery can jump onto a rear-pivot machine. A very significant distinction between how these two units work depends on which part of the equipment extends outside of the turning radius.