Question Off-ramps: Answers Are usually safe for trucks. Can be dangerous for trucks. Should not be used by trucks. Should be used only if following another vehicle. Explanation The combination of slopes and curves can make freeway on- and off-ramps dangerous for trucks. Remember that posted speed limits on ramps may be safe to be driven by cars but too fast to be driven by large or heavily-loaded vehicles. This questions appears in the following tests: Montana Passenger Nebraska Double New York Class B Knowledge Test New York Passenger Pennsylvania Class A Knowledge Test