TAMPA - Proponents of light rail in Hillsborough County have focused on development that has occurred along routes in other cities.

But a new study shows that the Northeast route long considered more beneficial to development and with slightly higher projected ridership would cost millions of dollars more to establish because of costs to acquire CSX railroad right-of-way.

The 126-page study to be presented to the HART board Monday also says the route from downtown to Tampa International Airport along Interstate 275 rather than along Cypress Street would attain higher ridership, though at a slightly higher development price.

Advocates believe more redevelopment opportunities are available along CSX tracks for about six miles to the north rather than along I-275, before the route heads northeast to Cross Creek beyond I-75. The CSX route would initially draw 19,500 daily riders, 3,000 more than I-275.

However, the report said the "ballpark" estimate to buy CSX right-of-way, which the freight railroad insists must include the purchase of 95 miles of track extending into Pinellas and Hernando counties. That would add $679 million to the $1.5 billion CSX route capital costs, compared with $1.7 billion along I-275.

No cost projections have been developed yet for alternative agreements to use CSX right-of-way, though that, too, is expected to be pricy. Travel time from Cross Creek to downtown along the CSX route would be 59 minutes, compared with 52 via I-275 and 62 by auto, the report said.

"The CSX alternative has a slightly higher projected ridership and a greater redevelopment potential than the Interstate alternative," the report said. "It should be noted, however, that many light rail projects operating in freeway corridors have experienced significant transit oriented development at stations," citing examples from Dallas, Denver and Portland.

The I-275 light rail route between downtown and the airport would cost $1.1 billion to build compared with $950 million along Cypress Street, but would draw 2,000 more daily passengers – a total of 6,250. Rail travel time through Tampa International to Hillsborough Avenue, where multiple bus connections would be available, would be 25 minutes compared with 19 by auto.

Voters on Nov. 2 will decide on whether to raise the sales tax one cent on the dollar to provide funds for light rail and for bus and highway improvements. Some of the additional tax money could used to obtain federal matching funds to build both routes.

"Transit systems are increasingly pursuing strategies to advance several corridors at one time," the report said, citing Salt Lake City, Houston and San Francisco.

As another option if the referendum passes, HART could use the new tax revenue to build the downtown-to-airport connection without federal matching funds. That would simplify project work and light rail could serve the downtown high-speed rail station by 2015, three years earlier than if HART used federal funds for both routes.

CSX's insistence that tracks be purchased beyond Hillsborough County could put a right-of-way opportunity in the lap of the Tampa Bay Area Regional Transportation Authority. Those CSX lines could be used to establish commuter rail between Hernando, Pasco and Pinellas counties.

tjackovics@tampatrib.com(813) 259-7817