The Orange County grand jury is calling for transportation officials to devise a plan within a year aimed at constructing a light-rail network that would link densely populated local cities and ultimately connect to transit systems in Los Angeles.

Such a plan would mark an aggressive shift in Orange County, which has lagged behind neighboring San Diego and Los Angeles counties in planning for and building a regional light-rail network that reduces air pollution and road congestion.

In recent years, Santa Ana, Garden Grove, Anaheim and Fullerton have begun planning or studying streetcar systems – currently in various stages of conception – to run along relatively short stretches within their borders. While the grand jury commended those efforts, it found that there is no comprehensive plan for a regional system, and called on the Orange County Transportation Authority to develop one.

“These steps, although incremental, provided a much better venue for local political and public consideration,” the grand jury wrote in its report released last week. “OCTA’s role took the place of the ‘core city’ presence that had characterized both Los Angeles and San Diego over the past 25 years.”

Garnering widespread support for light rail has proved politically unpopular in the past few decades, when plans for larger networks have withered after residents opposed their high costs, questioned their benefit and argued they would serve only a small portion of the county.

Those disagreements highlight a debate that has dragged on for years in Orange County: What’s the best way to spend money to improve mobility and ease congestion – roads or rail?

In the 1980s, faced with increased air quality concerns, Los Angeles and San Diego counties began constructing light-rail systems. Since then, Los Angeles’ network has grown to 79 miles and San Diego’s to 76 miles.

“These networks have been largely successful in helping to reduce traffic congestion and smog by reducing the number of automobiles on the roads,” the grand jury wrote.

As its neighbors built train systems, Orange County chose instead to spend on building and improving roads. The grand jury blames that trend partially on the divergent views and needs of the county’s 34 cities, but also on locals’ mistaken views that the county isn’t urbanized and is better served by cars, buses and freeways.

In fact, the report points out that Orange County has a population density 57 percent greater than Los Angeles County and five times greater than San Diego County, according to 2010 U.S. census data.

“There is no demographic answer as to why light rail system development is more readily supported in both Los Angeles and San Diego Counties than in Orange County,” the report states.

To convince the public of the need for light rail, the grand jury calls for a widespread campaign to recruit more cities and residents to advocate for an interconnected light rail system.

Anaheim Mayor Tom Tait, who sits on OCTA’s board of directors, said such a plan would be disastrous – costing hundreds of millions of dollars, serving “less than one-tenth of 1 percent” of the county’s population, taking up lanes on congested roads and reducing bus routes by diverting operational funds.

“Light rail is the equivalent to a bus line that has no flexibility to it,” Tait said.

Since 2008, OCTA’s bus ridership has dropped by 30 percent, resulting in cuts to some service. Even the grand jury acknowledged concerns over that decrease.

But OCTA spokesman Joel Zlotnik said the agency is encouraged by light rail’s success elsewhere and confident that locals would use the system.

“OCTA strongly believes that building a streetcar will attract riders that may not routinely ride the public bus system,” Zlotnik said. “Santa Ana has the fifth-densest population of any large city in the nation and we believe the demographics are ideal for building strong ridership.”

Zlotnik said OCTA is working to create compatibility between Santa Ana and Anaheim’s planned streetcar routes. But he said the agency has no plans to link Orange and Los Angeles counties by light rail.

OCTA is seeking funding for the county’s light rail projects through the state’s Cap-and-Trade Program, Orange County’s Measure M2 half-cent sales tax and federal transportation programs.

Contact the writer: 714-796-7960 or jgraham@ocregister.com