 A month later , an environmental study was conducted that focused on the possibilities of rerouting the proposed freeway . In April 1972 , the majority of voters supported a referendum that halted plans to build the SR 78 freeway through the city of Escondido . The city then turned its focus to widening Lincoln Avenue and Ash Street instead , and also requested that the routing of SR 78 be moved to Broadway , Washington Avenue , and Ash Street from Grand Avenue to improve traffic flow . Five years later , signs were installed on eastbound SR 78 , directing traffic headed for the San Diego Zoo Safari Park to use I @-@ 15 south to Via Rancho Parkway instead of continuing eastbound , to bypass the Escondido traffic . 
