Section 372.237 - Cameron, Hidalgo, Starr, and Willacy Counties, TX(a) Transportation within a zone comprised of Cameron, Hidalgo, Starr, and Willacy Counties, TX, by motor carriers of property, in interstate or foreign commerce, not under common control, management, or arrangement for shipment to or from points beyond such zone, is partially exempt from regulation under 49 U.S.C. 13506(b)(1) .(b) To the extent that commercial zones of municipalities within the four counties (as determined under § 372.241 ) extend beyond the boundaries of this four-county zone, the areas of such commercial zones shall be considered to be part of the zone and partially exempt from regulation under 49 U.S.C. 13506(b)(1) .51 FR 1815, Jan. 15, 1986. Redesignated at 55 FR 42198, Oct. 18, 1990, as amended at 62 FR 15422, Apr. 1, 1997