Recent discussions of Mayor Bloomberg's congestion pricing proposal with local officials all across town seem focused less on the urban legend of "working masses who must drive to Manhattan" and increasingly on concern over the "flood of parking seekers around the edge of pricing zone." The fear is that motorists who used to commute into the core of Manhattan will avoid the $8 charge by parking in Brooklyn Heights, Williamsburg, Long Island City and the Upper East and West Sides, switching to transit there and adding to local traffic, parking and quality of life woes. How likely is a significant "border effect?" Is it simply the next refuge of status-quo advocates, or a problem the city should prepare to head off? The best answer is that it is impossible to predict or disprove the occurrence of future events, which is why the mayor has proposed congestion pricing as a three year pilot program. The before-and-after studies of the pilot would yield a wealth of information on the travel changes that congestion pricing would cause that no amount of sophisticated computer models, assertions by officials or neighborhood anecdotes can ever match. The plan says that if particular trouble spots emerge, then measures such as parking controls could be implemented. As far as predictions go, PlaNYC's modeling effort (see PlaNYC transportation technical report) calculated via a variety of transportation data and price elasticity inputs that an $8 charge will discourage over 7% of vehicle trips in the priced zone (Manhattan below 86th Street, excluding the perimeter highways) -- over 111,000 vehicles. It also finds that over 110,000 of these vehicle trips are also avoided city-wide, indicating that the overwhelming majority of these trips do not divert to other parts of NYC--they are made by another mode or foregone altogether. In concert with this finding, 94,000 people would be added to the city's transit ridership (including trips from the suburbs into the city). That is in keeping with Transportation Alternatives' 2006 "Necessity or Choice" report, which found that 90% of CBD-bound car commuters live in areas where mass transit is the predominant method of commuting (see MTR #548, www.transalt.org). This anticipated vehicle trip reduction should significantly improve, not worsen, traffic conditions around the edge of the zone, because of the way NYC's river crossings and Manhattan's corridor geography concentrates traffic as it nears the central business district. It's worth noting that about 30% of the avoided car trips, according to PlaNYC, take place completely within the priced zone south of 86th Street. Certainly none of these diverted trips could contribute to a "border effect." On the other hand, worry over such an effect is not founded on any analysis, or on experience in other cities that employ congestion pricing. It appears to entertain the idea that the $8 charge will create a titanic shift in travel behavior. Additionally, some seem to think that the motorists who are deterred will carry out their usual car commutes until they come close to the pricing boundary, and then suddenly divert to avoid paying. "There will be a crush of cars circling around 86th Street looking for parking spots that don't exist" East Side Councilwoman Jessica Lappin said at a recent hearing. "I envision idling, and more congestion, and more pollution in the air, because there aren't places for these cars to go." This scenario is absurd, for a variety of reasons. First, the $8 fee is not that expensive within the region's universe of transportation options. Half of the drivers entering the Manhattan CBD today pay a toll in that ballpark, crossing the Hudson or at an MTA tunnel or bridge. Carpoolers who can split costs will not be deterred, since two in a car would not pay much more than the price of two round trip city transit fares (depending on MetroCard option). Some drivers will welcome the chance to pay for improved driving times within the priced zone. Equally to the point, the time and convenience costs of finding a scarce or non-existent free parking space in dense areas outside the zone near a transit stop will not be worth it to most, who drive precisely because of the convenience. Changing to transit is much more likely near the beginning of diverted trips. Paying for parking outside the zone eliminates the cost advantage of not driving in. People are rational actors. Councilmember Lappin's scenario does not give them any credit for planning ahead, absorbing information and making clear cost-benefit choices about the monetary, time and convenience implications of their travel choices. As residents of the city and the metropolitan region, we know otherwise. We all have travel choices and make those calculations every day. Mayor Bloomberg proposes a test that would shift the terms of those choices somewhat (not radically, as some have claimed). It deserves to be tried.