Alabama
Must be reasonable and proper.
Vehicles towing trailers or semitrailers may not exceed a rate of speed that causes lateral sway.
Speed limits are 70 mph on rural interstates; 55 mph on urban freeways; or as posted.
45 mph is maximum when towing house trailer.
No trailer carrying a gross weight of load in combination with a vehicle in excess of 4,000 lbs. shall be operated at a speed over 10 mph unless equipped with suitable brakes controlled by the operator of the towing vehicle.
Unless otherwise posted, 30 mph in business and residential districts, and 55 mph at any time at all other locations. Turnpike and other designated highways 65 mph, except where posted 70 mph (minimum speed 50 mph).
Boat or utility trailer, same as passenger car; house trailer, 55 mph, day, 50 mph, night for brake-equipped trailers 15 to 32 feet long, 50 mph for trailers without brakes less than 15 feet; all others, 45 mph.
A person driving a passenger vehicle pulling another vehicle or trailer shall not exceed the posted speed limit.
No person shall operate any motor vehicle when towing a mobile home at a rate of speed in excess of 50 mph.
Rural interstate, 75 mph; non-interstate multilane highways, 70 mph; 2-lane highways, 65 mph, if posted. If not posted, 55 mph.
Any vehicle towing a trailer, any camper, and any vehicle with a registration weight of 8,000 lbs. or more must drive in the right lane of all roadways having 2 or more lanes for traffic proceeding in a single direction.
As posted. Fixed maximum limits as follows: (1) rural interstate highways – 65 mph; (2) residential districts on most local highways – 25 mph; (3) urban districts – 35 mph; and (4) in other locations – 55 mph.
Manufactured, modular, or mobile homes must not be transported at a speed in excess of 10 miles below the maximum posted speed limit when the maximum posted speed limit is in excess of 45 mph, and never in excess of 55 mph.
A person driving a vehicle towing a house trailer must not drive faster than 45 mph.
65 mph on secondary highways except where posted. 75 mph on interstate except where posted.
Same as for passenger cars according to the zone, but maximum speed for heavy motor vehicles is 10 mph less than permitted in any zone.
Unless otherwise posted, 50km/hr in a municipality, 90 km/hr outside a municipality.