Protesters and police prepare for a showdown: The city has created a route, agreed to by the organizers, that involves a giant U-turn for the marchers, who will travel from Union Square to Madison Square Garden and back. The organizers have asked the participants to complete the route, even though the turn downtown will take them about a mile farther from Central Park. After the march is over, the protesters will eventually be able to make their way uptown to the park, the organizers say. City officials say that there is nothing to stop people who are abiding by the law from going there - once they have moved out of the parade route's frozen zones, which will end around 32nd Street and Fifth Avenue. ...Tomorrow's parade will also involve a long diversion from the ultimate - if unofficial - destination. Conor Clarke, a college student who tried to reach last year's protest, said that the city again seemed to be making matters difficult by denying a permit for Central Park, which he saw as a sensible site for the protest. "I think the city is playing hardball, in sort of a nonrational way," he said. Paul J. Browne, the Police Department's chief spokesman, said that the gates to the park would remain open. After marchers move south on Fifth Avenue and reach 32nd Street, they will be able to leave the route and walk to Madison Avenue, Mr. Browne said. They will not be allowed to walk on the roadways. "We are not going to permit another en masse march to the park - you can't take over the streets without a permit," he said. "If people are walking on the sidewalk and not otherwise breaking the law, they can walk in any direction they want." Actually, people take over the streets without permits all the time.