The Bay Area Toll Authority (BATA) in Northern California is reminding the operators of tractor-trailers and other vehicles with more than two axles that a one-year exemption from an increase in bridge tolls instituted last year comes to an end this summer. The agency said the first step in the two-phase toll increase for multi-axle vehicles takes effect July 1 and will remain in place through June 30, 2012.

During this period, BATA said the toll for three-axle vehicles or combinations on the region’s seven state-owned toll bridges will increase to $10.50 from the current $6. Tolls for four-axle vehicles will rise to $14 from the current $8.25; tolls for five-axle vehicles will climb to $18 from the current $11.25; tolls for six-axle rigs will go to $21 from the current $12 and tolls for vehicles with seven or more axles will increase to $24.25 from the current $13.50.

On the Golden Gate Bridge, toll rates for customers who pay cash will be set at $13 for three axles; $18 for four axles; $22 for five axles; $27 for six-axles; and $31 for vehicles with seven or more axles.

Discounted tolls for customers who pay their tolls with “FasTrak,” an electronic payment system, will be set at $11.25 for three axles; $15 for four axles; $18.75 for five axles; $22.50 for six axles; and $26.25 for vehicles with seven or more axles.

Beginning in July 2012, tolls for vehicles or combinations with three or more axles on the seven state-owned toll bridges will be fully indexed at $5 multiplied by the number of axles, or $15 for three-axle vehicles; $20 for four axles; $25 for five axles; $30 for six axles; and $35 for rigs with seven or more axles. The fully indexed toll rate on the Golden Gate Bridge will be $6 multiplied the number of axles, with a $5-per-axle rate for FasTrak customers.

BATA said the two-step increase in tolls for multi-axle vehicles on state-owned bridges is part of a comprehensive toll increase package to finance seismic retrofits of the Antioch and Dumbarton bridges, to help offset the increased cost of debt financing resulting from financial market turmoil that began in 2007, and to counter revenue losses caused by a decline in toll-paying traffic on the bridges since fiscal year 2003-04.

While the toll hike went into effect in July 2010 for most vehicles, the agency noted the increase for multi-axle vehicles was delayed for one year to allow commercial trucking firms to incorporate the higher tolls into new contracts with shippers.