The dataguide told me how much to expect to pay for a taxi—and had offered hints on how to barter the driver down to the proper amount. It had also warned me against accepting a ride from the throng of "taxi" drivers who cluster outside the arrivals gate. They were the ones whose cars had non-standard GridGuide software—or worse yet, who fell back upon their own navigational abilities. According to the guide I’d slotted, at least once a week one of these carcachas wound up crunched against a divider or smashing head-on into a vehicle that was going the right way down a one-way street.