Lawrence, Kan. — Once in a while these days a carload of visitors turns off Interstate 70 toward Lawrence in search of the missile silos. Longtime residents of this friendly university town in the midst of flat Kansas wheat country patiently explain that the Minuteman missiles that 100 million Americans saw launched on their television screens Nov. 20 in ABC's ''The Day After'' were only props.
It's been well over a year now since the movie cameras were rolling here on the controversial film that simulated the effect on Lawrence of an atomic attack on nearby Kansas City. Some 200 residents and students here had temporary acting jobs. Hundreds more volunteered as unpaid extras.
The excitement level was high. ''That's all we talked about here for awhile, '' recalls Tracy Kite as she waits on the regular steady stream of morning customers at Jennings Daylight Donuts on Massachusetts Street, the city's main shopping corridor, which appeared strewn with debris and abandoned cars in the movie.
But more than a month has passed since the well-publicized television event that put Lawrence on the map for many Americans. And this community of 52,000 has been sitting back to take stock of all the increased attention coming its way.
The movie's most tangible effect has been economic.
A study by the local University of Kansas Institute for Economic and Business Research suggests that the filming itself, including ripple effects, jacked up the area's income by a sizable $2.1 million.
The cooperation between townspeople and ABC Circle Film personnel was such that John A. Myers, director of the Lawrence Convention and Visitors Bureau, predicts that Lawrence would get ''glowing reviews'' from ABC if and when the reference was needed.
''I do think all this will have some impact on our ability to bring additional film companies to town,'' Mr. Myers says. ''The relationship between the people of this community and ABC was absolutely unbelievable.''
And Lawrence officials are also hoping there may be some softer economic spinoffs from the increased name recognition. One Texas manufacturer, prompted by the movie to look up Lawrence on the map, recently phoned an offer of a Midwestern dealership to a Lawrence businessman.
''It may give us a little edge over another town of the same size in trying to attract a modest-size convention - it certainly makes us better known,'' says Lawrence Mayor David Longhurst. He recently attended a National League of Cities conference in New Orleans where other mayors often asked what he thought of the movie and if Lawrence was really ''still there.''
''I don't know exactly what the impact is, but it certainly isn't negative,'' Mr. Meyers says.
Though it has no direct connection with the film, industrially diverse Lawrence (there are Quaker Oats, TRW, and Hallmark plants here among others, and unemployment is a low 3.5 percent) recently hired its first economic development director. And a new research park site is being cleared in the hope of attracting a number of chemical and pharmaceutical firms, areas in which the university is particularly strong.
No stranger to controversy, Lawrence was settled in the 1850s as a ''free state'' or antislavery center and lost 150 local residents in a massive 1863 raid on the town by a self-styled general named William Clark Quantrill and a group of proslavery advocates. And last year Lawrence voters approved a nuclear freeze referendum by a strong 74 percent margin.
Yet the content and message of ''The Day After,'' and the publicity surrounding it, have had a distinctly divided impact on the Lawrence community.
''Some people are annoyed by all the attention from the news media and wish everybody would just leave us alone, while others are flattered by the attention but didn't think much of the movie,'' Mayor Longhurst observes. He pulls from a desk drawer in the local printing shop he runs a two-page handwritten list of newspapers and broadcasters (from a television station in Yorkshire, England, to a radio station in Guam) who have contacted him.
''Most people around here don't think there was anything much to the movie,'' insists Shirley North, a waitress in the doughnut shop. ''It was another war movie - so what?''
''People here, including the schools, weren't nearly as uptight or psyched up about the film . . . as much of the newspaper publicity suggested,'' agrees Lawrence School Superintendent Carl Knox. ''It was more of a low-key thing.''
But others argue just as strongly that the movie raised an important subject that deserves more attention from the average citizen. Since the film, US missiles have been deployed in West Germany and the Soviets have walked out of the arms talks in Geneva.
''It definitely made all that seem closer to home,'' says Keri Kinnaird, a graduate student in psychology, while waiting downtown to catch a bus back up to the campus. ''My friends aren't talking about it anymore, but hopefully it's all gone deeper.''
Harvey Shaw, an employee of the Lawrence Parks and Recreation Department who is stashing trash in plastic bags, says he saw the movie with his two small children. ''It made me want to get closer to my God. I feel we've been forgetting the importance of brotherly love and working together.''
F. Allan Hanson, an anthropology professor at the University who has long been active in the Lawrence Coalition for Peace and Justice and an offshoot committee focusing directly on the movie, says the film has intensified local interest in peace activities.
''My feeling is that the film moved a lot of people around here,'' says Professor Hanson. ''Some already intensely involved remained so, and some undecideds decided to take a stand. . . . And I suppose some people felt we better beef up our defenses - but they haven't called me.''
Mr. Myers argues that the film served more to alert than convert.
''I think it has certainly sensitized a lot of people here, but I don't think it's caused anyone to radically change his views,'' he says. ''Two years ago I would have been opposed to unilateral nuclear disarmament, and I still am. But I feel a greater sense of urgency now that we had certainly better to everything we can to keep open the lines of communication with the Soviets.''
To that end, Mayor Longhurst wrote some months ago to both Soviet leader Yuri Andropov and President Reagan to invite them to come to Lawrence to talk over prospects for easing the nuclear threat.
''We need to change the way we're approaching the problem,'' he explains. ''That isn't to say you lay down your arms, but you focus at least on trying to remove the nuclear threat instead of accepting a balance of terror as necessary. That doesn't seem very productive.''
Mr. Andropov politely declined Mayor Longhurst's invitation through the Soviet Embassy in Washington on grounds it would raise citizen expectations to too high a level. The White House told the mayor, through the Kansas congressional delegation, that the invitation is under careful consideration.