Leisure travel is fun, but its always possible to run afoul of any of a number of disasters. Bad weather, overcrowded hotels, giant trade shows, parades, political demonstrations, road construction projects, historic sites closed for renovation, transit strikes and so on. A few of these things might
be interesting to some travelers (parades) but others should be avoided for maximum pleasure on your trip.
For example, I once was in Washington D.C. and decided to check out the National Air and Space Museum. A long time Star Trek fan, the first thing I wanted to see was the original Enterprise model. The week I was in town, it was in storage. Curses!
What all of these problems have in common is a limited time span, some level of predictability or probability, and a wide variety of sources that would have to be consulted to gather this information.
Leisure travelers are often a bit flexible on the dates of their travel. "Oh, I'd like to take a week or so off in July or August, and go to Madrid." They need but know of the troublesome events, and adjust their schedule to avoid them.
Here is the solution. As an adjunct to a travel booking site, continually collect up all this trivia about various top destinations, and index it by city and date. When you start booking your flight to Los Angeles for instance, you could get a report like this:
LOS ANGELES TRIP, AUG 1 to 7:
Historical weather data for this period: x% Sunny, y% Cloudy, z% Rainy
Infrastructure: Highway 666 will have 3 lanes closed for widening, will severely affect airport traffic. July 17 to December 31, 2004
Event: The International Convention of Widget Harvesters. Aug 1 to Aug 7. Attendance: 52,000 Hotels: Hilton Downtown, Hyatt
Event: Association of People Who Do Nothing is planning a protest in Nada Park, August 4. Estimated attendance: 2000
Event: Transit workers contract comes up for renewal on August 5. Historical chance of strike: 19.5%
Attraction: Art Museum Picasso collection on loan to another museum. July 20 to October 1
Attraction: Wally World is closed for renovations the entire month of August
Armed with this information, you can tweak the schedule for your trip to avoid problems. Since I wanted to go to Wally World and see the Picassos, it looks like July is a better choice for me.
Of course it would be a large amount of work to keep this database updated. Perhaps volunteers in the destination cities could supply some of the data (like IMDB). Given the huge competition between the various travel booking sites on the Internet, it seems like this would be a good way for one of them to differentiate their offering.