The move is a result of Gov. George Ryan's recent decision to expand the I-PASS system to reduce congestion at toll plazas.
Authorities want to get about 100,000 trucks that already have toll authority charge accounts converted to I-PASS by Oct. 1. Tollway officials will spend $4.2 million for 150,000 more I-PASS transponders.
It is estimated that it will take about 10 seconds to move through a toll plaza with I-PASS, compared to 25 seconds currently. However, traffic planners have concerns about how the change will affect traffic patterns at toll plazas. Officials must decide whether to allow truckers access to all I-PASS lanes, to keep them restricted to the far right toll lanes as they are now, or something in between.