WASHINGTON — Twice as many Americans now commute from suburban homes to suburban jobs as those who commute from the suburbs to the central city, a report released Thursday shows.
Moreover, this trend is likely to continue, said backers of the national study, who urged transportation officials to focus on suburban growth and develop ways to improve roads connecting suburbs.
The study echoed 1982 findings by researchers at UC Irvine and other institutions showing that Orange County was leading the national trend. The research showed that the county had changed radically from a bedroom community serving employers in Los Angeles to a self-contained economic unit in which more than 80% of the home-to-work trips are within the county.
Suburb-to-suburb commuting has become "the predominant national commuting pattern," said the report, which was compiled cooperatively by transportation-related groups. It was released Thursday in Washington, D.C.
"The tremendous growth in suburban commuting has occurred in areas ill prepared, in terms of public facilities, roads and transit, to meet the challenge," it said.
The two-year study, "Commuting in America," was based on a comparison of 1960 and 1980 census data. It was sponsored by groups including the American Assn. of State Highway and Transportation Officials, the Highway Users Federation for Safety and Mobility, the National Governors' Assn., the U.S. Conference of Mayors and the National League of Cities.
The study found a dramatic increase in the number of jobs available in suburban areas, created by employers fleeing the congestion and high real estate costs of central cities.
In 1960-80, suburb-to-suburb commuting accounted for 58% of the increase in home-to-work trips in the nation, the report said. Commuting from the suburbs to central cities grew just 25%. Smaller fractions commuted inside central cities or from cities to the suburbs.
Suburbanites who work in central cities numbered 12.7 million in 1980, contrasted with 25.3 million who also work in the suburbs.
Francis B. Francois, executive director of the American Assn. of State Highway and Transportation Officials, told a press conference that unless transportation planners adjust to the trend, the United States will become "a nation in gridlock."
Mass transit options are far from adequate in suburban areas, the report said, noting that "the suburb-to-suburb market will represent . . . a very expensive-to-serve market for traditional forms of transit."
In 1984, Orange County officials sponsored a ballot measure to impose a 1-cent sales tax increase to help pay for projects that would ease congestion on the county's seriously strained freeway and road network. The measure was defeated by voters.
There have been other efforts in Orange County to curb growth through measures tied to traffic flow. A citizens' group is sponsoring a county initiative campaign aimed at barring major new construction projects except where traffic moves at an average rush-hour speed of 30-35 m.p.h.
Already, the commuter boom has increased the stress on the nation's interstate system as local commuters and long-distance traffic often compete for the same limited road space.
The study noted that suburb-to-suburb commuting trips are 50% shorter than those for people who commute from the suburbs to center cities for work. According to the study, the average commuter travels about 10 miles at an average speed of 29 m.p.h.
In Orange County, a 1982 study by UC Irvine researcher Mark Baldassare showed that the average commute is about 12 miles. About 40% of the trips lasted 10 to 20 minutes.
85% Use Private Cars
The shift to the suburbs has been accompanied by a dramatic increase in vehicle ownership. Most U.S. households have two or more vehicles, the report said, adding that 85% of the more than 110 million U.S. workers now use private vehicles to commute to work.
On another point, the report said it found little evidence to support the perception that more people are working at home.
"Popular expectations of the potential for working at home and alternative travel modes to appreciably reduce commuting by private vehicle have not been realized," the report said.
As a result, "highway demand has increased even beyond the high growth expected from the job boom."
Penny Pagano reported from Washington and Jeffrey A. Perlman from Orange County.