I-880 Northbound Safety and Operational Improvements at 23rd and 29th Avenues

Alameda, California

I-880 is a major corridor in California’s Bay Area region, connecting the Port of Oakland with Silicon Valley. High traffic volumes, nonstandard geometry, nonstandard interchange spacing and short weaving all contributed to the deficient flow of traffic and high accident rates in the vicinity of the 23rd Avenue and 29th Avenue interchanges.

Major project stakeholders included the California Department of Transportation, Alameda County Transportation Commission and the City of Oakland. To improve safety and operations at the interchanges, a five-stage plan was executed that included:

  • Phase 1:
    • Safety improvements to the northbound on-ramp
    • Safety improvements to the freeway mainline
    • Soundwall installation in the northbound direction between 29th and 23rd Avenues
    • Modification of local streets
    • Landscape enhancement
  • Phase 2: Reconstruction of the 29th Avenue overcrossing
  • Phase 3: Construction of the northbound I-880 off-ramp to 29th Avenue
  • Phase 4: Reconstruction of the 23rd Avenue overcrossing
  • Phase 5: Reconstruction of the northbound I-880 off-ramp to 23rd Avenue

The finished project includes ramp and intersection modifications and reconstruction, overcrossing structure replacements and construction of a new soundwall and re-directs regional traffic out of the neighborhood. The final structures better connect the cities of Alameda and Oakland and can now be used by school children within the Jingletown neighborhood, motorists, pedestrians and bicyclists.

This project has received the following industry recognition:

  • 2021 ACEC California Engineering Excellence Merit Award
  • ENR California Best Highway/Bridge (Northern California)


"Notably, this project included the first roundabout at an on-ramp in the Bay Area, which has opened new possibilities and proven that the roundabout option is viable. Future projects will draw upon these key learnings and continue to provide value to the engineering profession."

Nabaz S.
Associate Vice President and Public Works Operations Manager

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