Proposed Pacific Coast Highway Bikeway
Coastal Environments conducted a detailed analysis of the proposed Pacific Coast Highway Bikeway, which will extend approximately two miles along the coast from Coastline Drive to Temescal Canyon in the City of Los Angeles. The bikeway is needed to separate bicycle and automobile traffic. Segments of the bikeway will be constructed on existing level ground, on the beach (in order to avoid existing structures), and on riprap or fill slopes.
Coastal Environments evaluated coastal processes to assess risks from waves and possible future erosion of the proposed bikeway to minimize the potential for structural damage and loss over the design-life of the bikeway (25 years).
Wave-related damages to the bikeway were evaluated by:
1) using historical wave records to determine the extreme waves in the design life of the bikeway, and
2) computing the wave run-up for different wave storms at various points along the proposed bike path.
Geologic, geotechnical, and marine hazards were reviewed and quantified. Critical issues included:
- flooding of the bike path by wave run-up,
- estimating scouring depth at the toe of the riprap,
- the design of local fill slopes, and
- the sizing of riprap stone.