HARRISBURG — A new report bolsters the prospect of all-electronic toll collections on the Pennsylvania Turnpike, but any conversion would not occur for at least five years, officials said Tuesday.

The report by transportation consultants McCormick Taylor of Philadelphia and Wilbur Smith Associates of Columbia, S.C., recommends replacing the existing network of toll plazas with overhead “gantries” that would straddle the travel lanes near existing interchanges along the 545-mile system.

While motorists maintain highway speeds, tolls would automatically be deducted from their E-ZPass accounts and the license plates of other vehicles would be photographed so bills could be sent to their owners. Cash payments would no longer be an option.

Eliminating the need to slow down or stop at toll plazas would make the process of collecting tolls safer, faster and less harmful to air quality, according to the report.

“We have a lot of work to do before a final decision can be made, but this (report) is an important step forward,” said Roger Nutt, the commission's chief executive officer.

The conversion would cost an estimated $319 million, but it would boost net toll revenue by $5 million in the first year and by about $21 million in the 10th year, largely because of personnel savings as toll collectors are displaced, the report says.

Attempts to obtain comment from two Teamsters locals that represent the more than 700 toll takers were unsuccessful Tuesday.

Although the commission has not made a final decision on a conversion, it is preparing to solicit letters of interest as a first step in hiring a program management firm to address issues ranging from financial implications to public outreach.

If a conversion is approved, the company that is hired also would oversee other contractors that would be hired to implement the new system, commission spokesman Carl DeFebo said.