Art Dao, a long-time proponent for improving transportation in Alameda County will retire from the Alameda County Transportation Commission in December, he announced Friday.

As executive director of Alameda CTC, Dao helped steward billions of dollars in new county tax revenues to improve transportation and aging infrastructure in Alameda County.

During Dao’s tenure, Alameda CTC created the Bay Area’s first express lanes, the East Bay Bus Rapid Transit project, BART/Oakland Airport Connector, while easing traffic flow on the notoriously congested Interstate 80.

All of this was accomplished with the help of county voters who approved tax measures in 2000 and 2014 to fund many of the projects fronted by Dao.

Measure BB, approved by voters in 2014 created $8 billion in projects slated to be built over the next 30 years. A similar tax measure was famously defeated by just over 700 votes countywide in 2012.

Alameda CTC said the regional body will conduct a national search for Dao’s replacement.