What are the rules exactly? Let’s say you are leasing a semi, delivery van or courier vehicle for your logistics business. Since the truck is not something you personally own (or will ever own for that matter), you would like to limit the amount of alterations you make to the vehicle to insure a smooth transition when the terms of the lease expire. You also have to identify your vehicle with the proper GVW, MC, ICC or US DOT Numbers in order to be compliant with the DOT. According to the US DOT publication ETA 501c section 390.21 referencing vehicle identification the rule is this:

"Every commercial motor vehicle operated by a motor carrier in interstate commerce must be marked,

on BOTH sides of vehicle, with the following: 
вћ¤ The motor carrier’s name or trade name вћ¤ The motor carrier’s identification 
number, preceded by “US DOT” 
вћ¤ The size, shape and color markings must be in letters that contrast sharply in color with the background on which the letters are placed 
вћ¤ The lettering must be readily legible during daylight hours, from a distance of 50 feet."

 

* While it is true that the law does not specifically state a size or color requirement, it does say that it needs to be "legible" from 50 feet. The sign industry standard for block lettering to be read at 50 feet is 2" high. Other fonts and colors are perfectly legal, they just need to be sized a little larger to be read from a 50 foot distance.

Standard Ink Colors

Color Pallete


Gloss Black
Gloss White
Golden Yellow
Signal Yellow
Yellow
Light Yellow
Brimstone Yellow
Purple Red
Burgundy
Dark Red
Red
Light Red
Orange Red
Orange
Light Orange
Pastel Orange
Purple
Violet
Lavender
Lilac
Pink
Soft Pink
Deep Sea Blue
Steel Blue
Dark Blue
Cobalt Blue
King Blue
Brilliant Blue
Traffic Blue
Gentian Blue
Gentian
Azure Blue
Sky Blue
Light Blue
Ice Blue
Turquoise Blue
Turquoise
Mint
Dark Green
Forest Green
Green
Grass Green
Light Green
Yellow Green
Lime-Tree Green
Brown
Nut Brown
Light Brown
Beige
Cream
Dark Grey
Grey
Telegrey
Middle Grey
Light Grey
Silver Grey
Gold