For the week between Christmas and New Year's, it seems that all roads lead to Disney World: The week is one of the two busiest in the year for what has become the premier tourist attraction in the United States.

While Disney does not release annual attendance figures, stock analysts and others put the number at 30 million to 35 million, or 673,000 a week. But Christmas week and spring vacation week are well above average. This year, officials at Disney World expect the crush to begin on Dec. 22 and be at its most intense from Dec. 26 to Jan. 4 or 5.Half of these visitors will arrive by car, probably using one of the five main routes to Orlando. Families planning this trip should anticipate delays caused not only by the weather but also by repair work on the now middle-aged Interstate system.

According to Michael Camarano, data research manager at the American Automobile Association, most of the construction at sites south of the North Carolina-South Carolina line will continue all winter.

North of the border, construction would normally be inactive by now because concrete cannot be poured in cold weather, though bridge work may continue.

However, the weather in the North has been eccentric, and construction could continue if the weather is unseasonably warm. Generally, though, the construction season ends Dec. 1 and begins April 1.

Even where the crews have paused in working, drivers may encounter delays. And roads that are being straightened or widened, such as the New Jersey Turnpike, may still slow traffic because of diversions and constrictions of lanes.

Following are directions and a guide to road conditions on routes to Disney World, as outlined by Camarano. Estimated driving times do not allow for construction delays.

From New York: New Jersey Turnpike; I-95 to Daytona Beach; I-4 west to Orlando. Total: 1,102 miles. Estimated driving time: 19 hours 15 minutes.

The New Jersey Turnpike is being widened to 12 lanes from 6, sometimes creating delays in rush hours, so this stretch should be driven at nonrush hours. Delays and reduced speeds are expected at all construction zones throughout the state.

At Baltimore, construction on a toll plaza at the Tydings Memorial Bridge is causing lane and ramp closings with delays and detours. These will cease in the cold weather.

Elsewhere in Maryland, there is night construction on I-95 at Route 450 and at U.S. 50; entire lanes will be shut at 15-minute intervals from 11 p.m. to 5 a.m. On I-95 between Route 175 and Route 32 at Jessup, construction will slow traffic and limit it to two lanes. Construction work on both of these might continue until spring.

At Richmond, 20 miles of rough road will create delays; actual work on this is due to begin soon.

On the Virginia-North Carolina border, there is a 20-mile stretch of rough road while widening and bridge replacement go on. There will be lengthy delays in both directions at peak hours, which are expected to continue through the winter. Northbound traffic on the weekends can use U.S. 301 to bypass this.

In Jacksonville, Fla., detours have been posted because of bridge work on I-95 and Route 13. Taking I-295 in rush hours will avoid the problem.

From Buffalo: I-90 to Erie, Pa.; I-79 to Charleston, W. Va.; I-77 south to Columbia, S.C.; I-26 to I-95 in South Carolina, where drivers can pick up the New York City route. Total: 1,243 miles. Estimated driving time: 21 hours 15 minutes.

On the New York Thruway ramp, closings and lane restrictions are expected to continue for a year on the Niagara Section. This work will be interrupted over the winter.

At Charlotte, N.C., lanes are being widened on I-77, with possible shunts and delays. In Columbia, S.C., street construction is creating backups and delays on I-77 during rush hours.

From Detroit:I-75 south to I-285 around Atlanta; I-75 again to I-475 at Macon, Ga.; I-75 again to Wildwood, Fla.; then onto Florida's Turnpike south to I-4 east to Orlando. Total: 1,166 miles. Estimated driving time: 20 hours.

In Detroit, until cold weather prevents construction, there are seven miles of one-lane traffic both ways on I-75 from I-275 to the Wayne County line. Ramps are closed and will remain closed from I-275 south to I-75 northbound and from I-75 northbound to the South Huron River and Newport roads.

Ohio has a major construction compaign going on. In Findlay, things will be tied up all winter on I-75 between Exits 145 and 164 with detours and road widths restricted to 11 feet. In Dayton, there has been major construction on I-75 with lane closings and speed reductions. I-70 or I-675 should be used east of Dayton if this has not been completed by now.

At Cincinnati, going into Kentucky, there are expected to be lane restrictions all winter because of repairs on an Ohio River bridge; I-275 may be used as an alternative, but the elapsed time is about the same.

In Lexington and Berea, Ky., some construction may cause delays.

In Tennessee, there is construction south of Jellico and at Chattanooga, causing possible delays.

In Georgia, there may be delays in Atlanta south of I-285 and at Macon south of I-475.

From St. Louis: I-64 east to I-57 to I-24 to Chattanooga; then I-75 south to I-285 around Atlanta, where drivers can pick up the Detroit route. Total: 1,001 miles. Estimated driving time: 17 hours.

Illinois has had a major construction campaign, but this is shutting down for the season. All that should remain is work in Johnston City.

From Houston: I-10 to Baton Rouge, picking up I-12; then I-10 again to I-75 at Lake City, Fla., to Wildwood, where drivers can pick up the Detroit route. Total: 971 miles. Estimated driving time: 15 hours 45 minutes.

In Louisiana, between Lafayette and Henderson, there is a 12-mile rehabilitation project that reduces traffic to one lane; also some delays at Baton Rouge.

In Alabama, there is rough road south of Mobile on I-10 to the Mississippi border. This is due to be finished next spring.

Canada has a new auto regulation aimed at reducing daylight head-on collisions that may surprise drivers from the United States: Starting with the 1990 model years, all Canadian-registered vehicles must include a device that switches on headlights when the ignition is turned on.

Jim White, the head of crash-avoidance standards for Transport Canada, the federal agency, said that the daytime lights are less bright than the night lights, but brighter than parking lights.

However, visitors' cars are exempt from the regulation. (If drivers turn on their regular headlights, explained Michael S. McNeil, president of the Canadian Automobile Club, the tail lights also come on, and this may look like brake lights to cars following.)

McNeil says he often drives his auto, equipped with day lights, into the States.

"And the oncoming autos blink at me," he said.

"Probably they are reminding me that I forgot to turn my lights off. So I can't tell any longer if they are warning me about a speed trap ahead.

"But," he added, "of course, I always observe the speed limit."