The Metro ArlingtonXpress, otherwise known as MAX, bus route has gained some good footing during its first year of operation.The second part of the test is still ahead: whether the service from downtown Arlington and the University of Texas at Arlington to the Trinity Railway Express CentrePort Station can increase its ridership now that it’s a known quantity and UT Arlington students are back for a new academic year.Riders have logged more than 64,600 one-way trips on MAX since service began last August, Star-Telegram writer Susan Schrock reported.The average number of trips per day has ranged from 134 during one December week to 331 during a week in June. The target is to reach a solid 250-500 trips per day by next August, the end of MAX’s planned two-year trial.Then it will be time for sober analysis, not only for the future of MAX but also for what it means for public transit in Arlington.The bar for wider service is high, perhaps impossibly so. Arlington voters rejected increased sales taxes for public transit three times between 1980 and 2002.The city and UTA have grown greatly in 12 years. But whether that’s enough to make broad transit service feasible — and salable to voters — is a long shot.The pressure to make that judgment as soon as the two-year MAX experiment is done will be great.The pilot program is operated by Dallas Area Rapid Transit and the Fort Worth Transportation Authority, the T. The cost is $1.4 million, half paid by a grant and half by the city, UTA and the Arlington Chamber of Commerce.DART rules say that contract services, like MAX, in nonmember cities, like Arlington, must end after two years unless the city begins the process of passing a 1-cent sales tax for DART membership.That would be about $50 million a year from Arlington. Pigs might fly first.A more likely avenue, if MAX succeeds, might be additional contract services from the T.