When I first served on the Crescenta Valley Town Council, I attended one of the early presentations from the California Department of Transportation on the beginning of the State Route 710 Geotechnical Study.
At that time, it seemed inconceivable that a tunnel to connect the 710 Freeway to the Foothill (210) Freeway was even being considered, and no one in the valley seemed to take the plan seriously. We now know that Caltrans is determined to build this tunnel, no matter what.
The impacts of the tunnel extension on the Crescenta Valley would be overwhelming, while not benefiting overall traffic congestion.
According to an analysis done by La Cañada Flintridge officials of a Southern California Assn. of Governments study, if the tunnel is completed, 75% of surface streets, such as Fair Oaks Boulevard, Fremont Avenue, Los Robles Avenue and Atlantic Boulevard, would still be gridlocked.