It should be no surprise to anyone by now that the North Texas Tollway Authority is serious about collecting tolls on the growing number of pay-to-drive roads in the Dallas-Fort Worth area.In fact, the agency collects a lot in tolls, approximately $400 million last year, according to data on its website, ntta.org.But there's no real choice about this get-serious approach. Because tolls have become a major source of funding for big-ticket road projects in North Texas, we're all going to be driving on them more.NTTA collects the tolls on its own projects, of course. But it's also under contract to serve as a collection agency for most of the other toll roads in the region. So if you're driving on a North Texas tollway, most likely you're dealing with NTTA.The agency has to play the tough guy. If word gets around that consequences for not paying are small or non-existent, the system plain does not work.Most people who drive on toll roads pay. NTTA says it has distributed almost 2.4 million TollTags, electronic transponders linked to bank accounts or credit cards that bill drivers automatically. Because this region's pay roads don't have toll booths, those who drive without TollTags get billed.A comparative few don't pay, and NTTA is considering asking the Legislature for even tougher enforcement mechanisms to use against them.The agency already can levy fees in addition to the unpaid tolls, $25 per toll transaction up to a maximum of $200. The cost mounts fast.But there's more. State law says the toll scofflaws may also be charged the cost of a third-party collection service hired to get them to pay up. Finally, failure to pay is a misdemeanor subject to a fine of up to $250.Whether NTTA should have authority to go beyond those sanctions is a matter for legislative debate. For now, it's enough to say the tolls must be paid and NTTA is right to be aggressive about collecting.