Workers will begin removing trees on the south side of the roadway today and continue through October. Construction is expected to start in the fall.
The $1.05 billion project, originally slated to begin next year, was accelerated with the receipt of $50 million in federal stimulus funding.
Officials hope to complete the new Doyle Drive, to be called the Presidio Parkway, in 2013.
Other pre-construction activities including utility relocation are scheduled to begin later this month.
The collection of native seeds and plants in the area, to be grown in a nursery in the Presidio for wetlands and riparian habitat restoration projects, has already begun.