Interstate 40 enters Texas from New Mexico just north of Glenrio. The highway's first exit, exit 0, is for BL I-40-A, which serves the town of Glenrio. I-40 briefly runs through Deaf Smith County before entering Oldham County. The interstate gains frontage roads between exits 15 and 18 and turns from a northeast direction into a straight east direction. I-40 bypasses the town of Adrian before turning southeast. I-40 next bypasses the town of Vega, where it meets with US 385 at exit 36. The interstate briefly runs in an east direction through the town of Wildorado before turning back to the southeast. I-40 has a mostly rural route before becoming more suburban in Bushland, with housing developments becoming visible from the highway. The interstate passes by Cadillac Ranch before the Hope Road interchange and enters the city limits of Amarillo just west of Loop 335. I-40 expands from four lanes to six at Loop 335 and runs through a heavily developed area of the city. Near downtown, the highway serves as the northern terminus for Interstate 27 at a turbine interchange and begins an overlap with US 287.