Included in the widespread havoc caused by Hurricane Katrina is billions of dollars worth of damage to highways, roads and bridges all along the Gulf Coast.

Much of Interstate 10, a major east-west route across the U.S. from Jacksonville, Fla., to Los Angeles, is closed on either side of New Orleans. In the hurricane area, the impassible stretch extends from Louisiana to Alabama.

U.S. 90, which parallels much of I-10, also is heavily damaged from Louisiana to Alabama and is closed in many areas.

Months will be required to repair all of the damage to the heavily traveled I-10, the principal artery through New Orleans, as well as Highway 90. Sections of I-10 have pieces missing or misaligned, as if the highway were an unfinished jigsaw puzzle.

Additionally, sections of Interstates 310, 510, 610 and 55 are closed around New Orleans because of damage.

Many sections of the 5.4-mile, I-10 "twin span" bridge across the eastern edge of Lake Pontchartrain, which links Slidell and New Orleans, are missing.

East-bound I-10 also is closed in Mississippi from State Highway 57 to State Highway 613.

The east-bound lanes of I-10 near Pascagoula, Miss., are closed because a bridge shifted in the storm and must be realigned. Two big barges careened into the bridge's supports.

With I-10 out of commission, travelers on I-12 from Slidell, near the Mississippi border, west to Baton Rouge are likely to face major delays for months.

Parts of the 24-mile-long Lake Pontchartrain Causeway, the world's longest over-water highway bridge, are missing.

A section of I-55 south from Hammond, La., along the west side of the lake, into New Orleans also is closed.

Several U.S. 90 bridges were damaged:

· The bridge between Bay St. Louis and Pass Christian, Miss., was destroyed.

· The Point Cadet Bridge, a five-mile span on Highway 90 from Biloxi to suburban Ocean Springs, Miss., was damaged, forcing travelers into a lengthy detour on I-10 and I-110.

· The Cochran-Africatown Bridge on 90 shifted about two inches when an oil rig broke lose, floated down the Mobile River and slammed into the bridge. Traffic has been cut from four lanes to two. Plans are to jack up the bridge and realign it.

Highway 49 is open only to emergency vehicles from Jackson to Gulfport, Miss.

I-59 is shut down from Meridian to Picayune, Miss.

I-55 and I-20 are open, but officials are urging extreme caution and asking travelers to be patient.

While the damage list is extensive, most roads and bridges survive, require only to be cleared of sand and debris.

For those that were harmed, highway engineers are evaluating repair and replacement costs. Early estimates are that it will take years and billions of dollars to restore the road system to its former condition.

One of the highest priority projects is repairing the damage to the I-10 twin bridges over Lake Pontchartrain.

Louisiana's Transport Department opened contract bids Sept. 9, for replacing the numerous sections that were displaced by the hurricane.

The preliminary plan for the project calls for repairing the bridge in two phases. The first phase could be completed within 30 to 45 days with repair crews working around the clock, seven days a week. The second phase could be completed by January.