The southern portion of the project has the most restrictions in terms of permits and sensitive habitat considerations (primarily identification of endangered species nesting activity during certain months), which affect the allowable “windows” within which work may take place. As a result, there is less overall time to get the work done in the southern area. There are fewer such restrictions in the northern area. The contractor started in the south so that during the times impacted by those construction windows, potentially for several months, they can move to the north and continue making progress; then return to the south when the window is again open.
Additionally, the City requires one of the two trail access points to Belmont and Redwood Shores (in the southern area) to remain open at all times to reduce the impact of trail closures to residents, as well as for safety. This additional aspect also must be accounted for when sequencing the work.
Starting in the north could extend the project time significantly, thereby increasing the overall impact to residents. Sequencing the work in this way is intended to allow for completion of the project within the anticipated three years, thus reducing the overall length of impact to the community, while protecting the environment.