Interstate 10 (I-10) is a part of the Interstate Highway System that runs from Santa Monica, California, to Jacksonville, Florida. In Alabama, the Interstate Highway runs from the Mississippi state line near Grand Bay east to the Florida state line at the Perdido River. I-10 is the primary east–west highway of the Gulf Coast region of Alabama. The highway connects Mobile, the largest city in South Alabama, with Pascagoula, Mississippi, to the west and Pensacola, Florida, to the east. Within the state, the highway connects Mobile and Mobile County with the Baldwin County communities of Daphne and Fairhope. I-10 connects Mobile and Baldwin County by crossing the northern end of Mobile Bay and the southern end of the Mobile-Tensaw River Delta via the George Wallace Tunnel in Mobile and the Jubilee Parkway viaduct system between Mobile and Daphne. Route description I-10 enters Mobile County from Jackson County, Mississippi, near just north of where US Route 90 (US 90) crosses the state line near Grand Bay. The four-lane freeway has an eastbound welcome center ahead of its first interchange, a diamond interchange with the western end of State Route 188 (SR 188) due north of the center of Grand Bay. I-10 continues east-northeast through a partial cloverleaf interchange with County Road 39 (CR 39) north of Irvington. The highway crosses the Fowl River and curves more northeast through a diamond interchange with CR 30 (Theodore Dawes Road) west of the community of Theodore. I-10 expands to six lanes ahead of a pair of interchanges near Tillmans Corner: a partial cloverleaf interchange with US 90 (Government Boulevard) and a full cloverleaf interchange with SR 193 (Rangeline Road). I-10 enters the city of Mobile at Halls Mill Creek just east of SR 193. The highway has a directional-T interchange with the southern end of I-65, which serves Montgomery and Birmingham. I-10 continues northeast from I-65 as an eight-lane freeway that parallels CSX's NO&M Subdivision rail line. The highway has a complex interchange with SR 163 (Dauphin Island Parkway) just east of the Dog River; the interchange includes a flyover from southbound SR 163 to eastbound I-10 and a left-ramp flyover from westbound I-10 to southbound SR 163. I-10 and the railroad form the northern margin of Mobile Aeroplex at Brookley (formerly Brookley Air Force Base), along which the freeway has a partial cloverleaf interchange with Michigan Avenue. North of the airport, the interstate