ALBANY - The Spitzer administration on Wednesday waded into the debate on proposed state Thruway toll hikes.

Timothy Gilchrist, deputy secretary for economic development and infrastructure, asked the Thruway Authority's executive director in a letter to provide more information to justify the toll hike.

The administration expressed a series of concerns and said it wants more details on a range of items, including:

• What the authority is doing to minimize the impact of higher tolls on commuters.

• How the higher toll revenue will affect its credit rating.

• What will be the tangible results of its $2.1 billion road and bridge repair program.

• What the Thruway has done to control costs.

The Thruway Authority last month floated a plan to increase cash tolls by 5 percent in 2009, and another 5 percent in 2010, while raising the price of using the E-ZPass, the electronic toll collecting system, at slightly lower rates.

Those increases would be in addition to a previously approved 10-percent hike that begins in January.

Thruway Authority officials said the hikes are needed because fewer-than-expected drivers have been using the highway, and revenue collections have fallen short of the projections used when they developed their spending plans.

State lawmakers have blasted the proposed toll hikes, which they worry will have a ripple effect through the economy, particularly in upstate.

The state comptroller's office is reviewing the plan and is expected to release its findings by the end of this month.

Gilchrist in his letter said the Spitzer administration can't make a judgment on the proposed toll increase until it has answers to its own questions and has reviewed the comptroller's report.