Tobe Holmes of University City Partners describes changes coming to the UNC Charlotte part of the city when a light rail extension opens early in 2018. In the background is a new parking deck with retail on the ground floor, built by the Charlotte Area Transit System. Photo: Mary Newsom In the playbook for transit-oriented development, as a city adds more transit service it needs less parking. Here's the reasoning: Building too much parking is an incentive to people to keep driving. Parking lots and decks create large, unfunded environmental and health costs, including but not limited to the heat island effect, water pollution from gallons of storm water runoff and the American obesity epidemic from too much driving.As Charlotte’s Blue Line Extension light rail project nears completion (March 2018 is the projected opening), parking decks are rising along the line, including two huge decks near the UNC Charlotte campus where the line will end.  People who pay attention to such things ask whether we’re overbuilding parking. One recent example is this opinion piece from Charlotte Five – “It's insane to keep building huge parking decks along the light rail line.”The piece responded to a previous article - “It would be insane for Charlotte to stop building parking for apartments — right now.”Three thoughts about all that:1. I think both arguments are right. We need less parking in the long run, but for now we continue to need parking. (There is a whole other topic to be addressed, not here and not today, on how to shrink the number of surface parking lots being built.)2. In this case it’s not planners who should feel the most heat but lenders – who may not even know where Charlotte is and who won’t finance a project if the parking spots don’t fit their math formula. From what I see and hear most lenders don’t give a rip about good urbanism, diversity of uses, protecting surface waters, reducing obesity or any of that. They have their formula.3. This is an opportunity for creative, innovative building design – a flexible parking desk structure that could adapt, as the city becomes easier to navigate without a car, into something else.Here’s why we can't instantly get rid of parking, happy though I would be to be arguing the other side of this. Most of the acreage in Charlotte, like most Sun Belt cities, was built to make driving easy, not walking or biking or transit. In huge parts of the city only the brave, the masochistic or the desperate choose to walk or bike to destinations. Yes, a few older neighborhoods break that pattern – Dilworth, Plaza Midwood, NoDa, etc.  Most Charlotteans don't live there.Consider: UNC Charlotte is nearing 30,000 students, plus 4,000-some faculty and staff.  We can all agree that encouraging more of them to use transit is ideal. With more people taking transit the campus can build fewer large expensive parking decks. But people live all over the city. Using transit to get to the campus is huge time investment requiring walking long distances to a bus, which may run only every 30 to 45 minutes, then riding to campus or to a light rail station. Only two bus routes serve the campus; one originates uptown, the other at SouthPark mall (that route will probably change as part of other transit changes to campus). Most people will not choose to invest 90 minutes or more for a trip they can drive in 20 to 30.The city's bus service is better than in 1998, but nowhere near what it needs to be. The Charlotte Area Transit System is studying its bus routes, but is not well-funded enough to simultaneously build light rail and dramatically improve bus service.Consider people living near the light rail. Some did opt to live there so they can take the rail to work. But people change jobs and the new one may not on an easy transit route. Jobs are spread all over the city, with only a sliver of them easily reachable by the lone light rail line. And people acquire roommates, partners and spouses whose jobs may not be transit-friendly. (See this 2014 piece, Car-free in Charlotte? It isn’t easy, by a writer who gave up on South End as too hard to manage without a car.)So for the foreseeable future, driving is necessary even for those of us who wish we could drive less. That means parking is necessary. For now. No, we don't need as many spaces as lenders require to be built. We should figure out how to incentivize shared parking, and work to minimize surface lots. But still.Yet couldn’t some of those ugly decks be repurposed in time? I’m not an engineer so maybe this is nuts, but I have to think that with innovative design and engineering, a parking deck could be designed to transition at a later time into residences or retail, with a much smaller share of parking.As the city densifies and transit grows more robust – we can always hope! – we can get by with less parking. And those ugly decks could sprout other, more congenial uses.