In March 2011, the American Public Transportation Association released findings that public transit could see a spike ridership if gas prices reach $4 per gallon. But how many of those could be school children?

It's an interesting question, especially since most transit agencies don't break down specific numbers of primary, secondary and higher-learning students who take the transit bus or metro train. In its May 2007 study* "A Profile of Public Transportation Passenger Demographics and Travel Characteristics Reported in On-Board Surveys," APTA found that these students, combined, account for 10.7 of all public transit riders based upon occupation. That's the second-highest number behind adults taking the bus or metro to and from work at 72 percent.

Based upon recent information, APTA says there are about 9.3 billion transit rides each year, similar to the estimated 10 billion student rides on school buses when factoring in regular route transportation and field, activity and sports-related trips.

School students on transit — and a spokesperson at APTA pointed out that the age range could include those in elementary school all the way up to senior citizens attending college courses — are followed by retired people at 6.7 percent, the unemployed at 6.4 percent. About  2.2 percent area classified as "other employment," and homemakers make up the other 2 percent.

When it comes to "trip purpose," another criteria used by APTA to track ridership, the data shows the same report says that 10.6 percent utilize transit to get to and from elementary, secondary and college classes. In comparison, APTA says that 59.2 percent of all transit trips are for the work commute. Shopping and dining is the trip purpose for 8.5 percent of trips, 6.3 percent of trips are for personal business, 6.8 percent are for social purposes, 3.0 percent are medical trips, and 5.7 percent are for other trip purposes.

Most school districts enter agreements with the local transit authorities to provide discounted fare to students who require transportation but are ineligible or unable to ride school buses.

A main concern of the school bus industry, especially that of private school bus contractor companies and the National School Transportation Association, is illegal competition. The Federal Transit Administration oversees transit operations at the federal level and how the municipal service relates to school bus operations.

The FTA's "Tripper Rules" prohibit transit agencies that receive federal subsidies from engaging in specialized transportation for school students when a private, for-hire school bus company exists in the area and is willing and able to provide route service to the school district. Namely, transit routes must be fixed and open to the public. Transit routes cannot be specially drawn to serve students getting to and from school.

Tripper service can be a tricky situation, one open to interpretation by the courts that has been the subject of about three dozen legal decisions on tripper service, most of which are noted on the FTA Web site. Sen. Patty Murray (D-WA) has recently been one of the more vocal opponents of the tripper regulations.

For now at least, school transportation has won out, but NSTA remains on the lookout for possible violations and at the forefront of a continued fight to thwart the ability of transit agencies to compete with private, for-profit school bus companies. And Sen. Murray has publicly stated that she will continue to fight for the King County Metro in Seattle. If she wins, the school transportation industry says, a precedent could be set nationwide.

Editor's note: APTA's surveys summarized the results of questionnaires completed by over 496,000 public transit riders sampled by transit systems that carry 60 percent of all transit trips in the United States.