ALMOST half of Houstonians would move away if they could, a recent poll showed.The next-best thing, voters in the nation's fourth-largest city apparently decided, was to shove incumbent Mayor Kathryn Whitmire out of office. And they passed a term-limitation proposal for good measure. Dissatisfaction over crime, education, a mass-transit proposal, and the economy led to Mrs. Whitmire's third-place finish, with 20 percent of the votes in Tuesday's election. Real estate developer Robert Lanier pulled in 44 percent, while state Rep. Sylvester Turner attracted 35 percent. Those two candidates will meet in a runoff election on Dec. 3. Whitmire was also hurt by the anti-incumbent mood. A term-limitation proposal for the mayor and city councilors carried by a 3-to-2 ratio. Advocates of the measure have joined forces with other groups to do the same to state offices. With five consecutive terms, Whitmire, Houston's first woman mayor, has been in office for more terms than any mayor in the country. She guided the city through the turbulent 1980s, at the start of which the oil boom collapsed, wrecking the city's economy. Some of the belt-tightening measures she adopted came at the expense of the police force. Her opponents blamed the decline in the number of officers for the surge in violent crime the city has witnessed lately. Both men promised to enlarge the police force. The defeat of Whitmire is a blow to a planned monorail project. Mr. Lanier, who had led Whitmire's campaign in the mid-1980s to sell a monorail to voters and then chaired the agency in charge of building one, later became convinced that it wouldn't solve the mass transit or air pollution problems of sprawling, car-wedded Houston. An angry Whitmire asked for Lanier's resignation from the transit agency, and he made opposition to the monorail a key element of his crime-fighting proposal by arguing that money from the transit agency's enormous surplus could be used to hire more police officers. Mr. Turner also opposes the monorail project in its current form. His good showing in Tuesday's election confirms that Turner could become Houston's first black mayor. Though far outspent in the election, Turner used numerous televised debates to impress white voters with his self-made success and moderate, consensus-building positions.