The commuters are bringing broad changes to the face of the countryside for 100 miles on all sides of the capital. Land prices throughout the suburban region are rising fast, and the few patches of farm or forest land that remain near major highways are quickly being bulldozed for strip malls and housing developments. At the same time, the commuters appear to be fueling economic growth in dozens of towns and cities. Schools, hospitals and other services in some suburban towns are being improved to meet middle-class standards. The daily commute here offers more daunting challenges than those faced by most straphangers and car-poolers in the United States and Europe.
Traffic jams are horrendous.
North of the border, commuters have been polled, profiled and analyzed ever since the United States Census Bureau first included questions about ''place of work and journey to work'' in the 1950 census. The 1990 census showed that 24 percent of all Americans were commuting to jobs in a county other than the one they lived in. In contrast, Mexican commuters have never been systematically counted, mainly because they have emerged in large numbers only recently. Based on calculations including revenues from highway tolls, she estimated that as many as 500,000 people may be traveling each day between the capital and six surrounding states. Probably a third of them are workers commuting to jobs, she said.