Concerns about health, safety and security had been raised in support of the plan approved Tuesday by the Amarillo City Commission. The measure takes effect later this month.
Some campers began moving Wednesday from the property that belongs to the Texas Department of Transportation.
Homeless advocacy groups in Amarillo have pledged to help the campers. Amarillo police have provided the campers with lists of shelters.
Violators face a Class C misdemeanor charge punishable by a fine of up to $500.