Update: 520 bridge tolling to start Dec. 29

The Washington Transportation Department says tolling on the Highway 520 floating bridge will begin at 5 a.m. on Dec. 29.

The department plans to use tolls to help pay for a new bridge project that will cost more than $4 billion. Pontoons are already under construction to replace the 48-year-old bridge with a new six-lane bridge.

The toll rates will vary depending on traffic, up to $3.50 during the peak commute. The toll will be automatically deducted from drivers with a Good to Go transponder. Other drivers will be mailed a bill with a $1.50 surcharge.

The department has been running ads telling Seattle drivers that tolling will start this month on the Highway 520 floating bridge across Lake Washington.