Golden Gate Bridge workers Friday erected a 27-foot electronic sign alerting southbound drivers to a new carpool lane being created.

Also under way is restriping to funnel eight lanes down to four at the toll plaza.

Both projects are being done in preparation for the permanent closure of manned toll booths on Wednesday. The tolls are being converted into an entirely electronic affair and no cash will be accepted.

The restriping and signage changes cost $35,000, said Gina Belforte, a Rohnert Park councilwoman who is a director of the bridge highway and transportation district.

The switch to electronic tolls is projected to cost $3.4 million. The change is expected to save $16.8 million over years, partly by eliminating 28 full-time toll workers.

District directors approved the carpool lane Friday. It will be the second lane from the right for southbound traffic.

— Jeremy Hay