Also the floor is 40' lon g plus the gooseneck out front so it is really a 48' trailer out of the box. Max length for one unit is 53' I believe.
Max legal trailer length is 53'
Max combined vehicle length varies state to state.
MODOT Rules;
Dimension Legal Maximum Permittable
Width 8’6” 16’
Height 15’ 16’
Length – Trailer & Load 53’ N/A
Truck-tractor semi-trailer combination
Length – Overall N/A 150’
Truck-tractor semi-trailer combinations
Length – Truck-trailer combinations 65’ N/A
Length – Auto/boat transporter 75’ N/A
Length – Towed units 65’ 150’
Length – Single units 45’ 60’
Weight – not to exceed 22,400 lbs per axle N/A None