The studies did conclude that a driver's skills, the distribution of the load, and the road conditions can all affect an LCV's stopping distance. With regard to braking, the percentage and length of a downgrade can present safety concerns. Because of their increased weights, LCVs typically must rely more on their brakes than tractor semitrailers or twin trailers. However, with properly adjusted brakes, long, steep downgrades may not present problems, since LCVs have more potential braking capacity than non-LCVs. Their increased weight means that LCVs must have the horsepower, engine torque, and drive-train efficiency to operate within the stream of traffic without excessive speed differentials that can cause problems for both the LCV and other vehicles on the roadway.
Crashes are more likely when LCVs travel under the prevailing speed.
Studies in both California and Utah also revealed that LCVs can have difficulty maintaining speeds when they travel on roads with moderate to severe grades. LCVs also pose safety problems in other areas. In addition, LCVs have trouble accelerating and merging with traffic on freeways. The LCV's lower acceleration speeds, coupled with its need for more longitudinal space, may also affect the roadway capacity. Both the Rocky Mountain double and turnpike double have more low-speed offtracking problems than either the tractor semitrailer or twin trailer.