See also:

Checking the Restraint Systems
Now and then, make sure the safety belt reminder light and all your belts, buckles, latch plates, retractors and anchorages are working properly. Look for any other loose or damaged safety belt ...

Speedometer
The speedometer shows the vehicle's speed in either kilometers per hour (km/h) or miles per hour (mph). ...

Weight of the Trailer
How heavy can a trailer safely be? It should never weigh more than 1,000 lbs (454 kg). But even that can be too heavy. It depends on how the rig is used. For example, speed, altitude, road grade ...