The introduction of SunPass on two Miami-Dade causeways is the latest in a series of initiatives to expand use of Florida’s electronic toll-collection system beyond state highways.

“We are hoping that a year from now, in 2014, the new system will be in place on both the Rickenbacker and then the Venetian Causeway,” said Michael R. Bauman, chief of the Miami-Dade public works and waste management department’s causeways division.

Originally, the county had planned to activate SunPass on the causeways in 2012, but the project was delayed because of contractor issues and efforts by all Florida tolling agencies to centralize back-office operations that include billing and other customer services, Bauman said.

Conversion of causeways’ C-Pass system to SunPass transponders will be one of the most significant changes in the history of the storied roads that carry tens of thousands of commuters every day to and from the mainland.

The 5.4-mile Rickenbacker, the longer of the two causeways, is also the newest. It opened in 1947. The 2.8-mile Venetian opened in 1925.

Tolls have been charged on both causeways for decades. The Rickenbacker was the first to adopt electronic tolling in 1997 with the C-Pass system, followed by the Venetian shortly after.

Both causeways still take cash at some toll plaza lanes.

While the plan is to eliminate cash tolls, Bauman said details are more advanced for the Rickenbacker than for the Venetian.

As a result, he said in an interview, details of how SunPass will operate on the Venetian remain undecided.

On the Rickenbacker, however, he said the toll plaza will be removed and its eight lanes will be reconfigured into four lanes with electronic gantries. Cash will no longer be accepted.

In both cases, said Bauman, lower annual tolls paid by residents and commuters served by the Rickenbacker and Venetian will be preserved under the SunPass arrangement.

The vehicles of residents and commuters already registered with causeway systems will be recognized by SunPass, and no additional toll charges will be made, Bauman said.

The current cash toll price on both causeways is $1.50. Whether that rate will remain once SunPass kicks in is still under discussion, Bauman said.

On the Rickenbacker and Venetian, residents with C-Pass transponders pay a flat $24 per year. Nonresidents who drive the Rickenbacker pay $60 per year and Venetian commuters pay $90.

Registration will continue, but it will be done online.

Drivers who don’t have SunPass will still be allowed to use the causeways. They will be billed later via Toll-by-Plate, Bauman said.