In addition to the official control cities of Galveston, Houston, and Dallas, I-45 serves a number of other communities, including La Marque, League City, Spring, The Woodlands, Conroe, Willis, Huntsville, Madisonville, Centerville, Buffalo, Fairfield, Corsicana, and Ennis.
U.S. Highway 190 joins I-45 for 26 miles from Huntsville, Texas to Madisonville, Texas. U.S. Highway 287 joins I-45 for 18 miles from Corsicana, Texas to Ennis, Texas. U.S. 287 signs are only posted (with I-45) from the northern end of Business Loop 45 in Corsicana to the Ellis County line.
Hurricane Rita evacuation from the Louetta Road (exit 68) overpassInterstate 45 gained notoriety during Hurricane Rita in 2005. Thousands of Houston area evacuees jammed the roadway trying to leave. As a result, the freeway became a parking lot. Gas stations ran dry and hundreds of people's cars simply ran empty, their occupants having to spend the night along the shoulder. Four-hour drives suddenly became 24-hour drives. Even though the Texas Department of Transportation started contraflow lane reversal at FM 1488, it didn't alleviate the traffic jam deep into the city, as that starting point was even north of The Woodlands, which is close to Conroe, the northern terminus of the greater Houston area.
At just 284.913 miles, I-45 is the shortest of the primary interstates (those ending in 0 or 5).
The stretch of I-45 connecting Galveston with Houston is known as the Gulf Freeway. It was the first freeway built in Texas--opened in stages beginning on October 1, 1948, thru a full completion to Galveston in 1952, as part of U.S. Highway 75. At the north (Houston) end, it connects to the North Freeway via the short Pierce Elevated, completed in 1967. The section north of the curve near Monroe Road/State Highway 3 in southeastern Houston was built on the right-of-way of the former Galveston-Houston Electric Railway, which entered downtown on Pierce Street.
After several interchanges, I-45 crosses the Galveston Causeway and passes Tiki Island. The split with State Highway 6 and State Highway 146 (to State Highway 3) may be the beginning of the Gulf Freeway; old U.S. Highway 75 south of this junction was upgraded on the spot.
The Gulf Freeway generally parallels State Highway 3 (old US 75) about 1 mile (1.5 km) to the west, bypassing La Marque, Dickinson and South Houston. It includes interchanges with several other freeways: the Emmett F. Lowry Expressway (Farm to Market Road 1764), NASA Road 1 Bypass (freeway under construction) and the Sam Houston Tollway, meeting the north end of State Highway 3 in southeastern Houston. (This part of SH 3 °™ on Winkler Drive and Monroe Road °™ is not part of old US 75.) A center reversible HOV lane begins just south of the Sam Houston Tollway.
I-45 and I-10 next to Downtown HoustonIn Houston, I-45 meets Interstate Highway 610 and State Highway 35 at a complicated interchange. At the merge with Spur 5, a short freeway spur to the University of Houston, elevated collector-distributor roads (also part of Spur 5) begin. The C/D roads and the HOV lane end at Dowling Street, the original end of the Gulf Freeway. Just past Dowling Street is an interchange with U.S. Highway 59 (Eastex Freeway and Southwest Freeway) and State Highway 288 (South Freeway), after which I-45 technically becomes the North Freeway as it runs along the northwest half of the block between Pierce Street and Gray Street as the Pierce Elevated.
The reversible high-occupancy vehicle lane begins in downtown Houston at the intersection of St. Joseph Parkway and Dowling Street, with easy access inbound to St. Joseph Parkway and outbound from Pierce Street. It runs down the median of the Gulf Freeway, mostly at the same level as the main lanes. Ramps are provided for access to and from the following roads:
Eastwood Transit Center - full access
Interstate Highway 610 north frontage road - full access
Monroe Road and Monroe Park & Ride - full access
Fuqua Park & Ride and South Point Park & Ride - full access
Frontage roads north of Dixie Farm Road (Farm to Market Road 1959) - towards downtown, with a ramp stub for continuation
The North Freeway HOV begins in downtown Houston near the University of Houston®CDowntown, with easy access inbound on Milam Street and outbound on Travis Street. Ramps and entrances are provided for access from the following roads:
Interstate Highway 10 westbound exit and entrance only - full access
Quitman Street - full access
Airline Drive (to Crosstimbers Road) - full access
N. Shepherd (to N. Shepherd Park & Ride) - full access
Farm to Market Road 525 (Aldine Mail Route) - full access
Kuykendahl Park & Ride - full access
Farm to Market Road 1960 (to Spring Park & Ride) - full access
The HOV ends approximately one mile north of the FM1960 exit.
The stretch of I-45 along the Julius Schepps Freeway in Dallas, from the Trinity River to Downtown Dallas, is elevated above the surrounding areas. As such, when ice storms hit the Dallas area (usually on average 1-2 times per year), the freeway is shut down, and traffic is diverted to State Highway 310 and U.S. Highway 175 which parallel I-45.
I-345 is just 1.4 miles (2.3 km) long and connects the end of I-45 to the end of US 75 along the east side of downtown Dallas. It is signed northbound as US 75 and southbound as I-45.