The Lilac Road Bridge is a reinforced concrete arch bridge in Bonsall, California, built in 1978 at a cost of $1,500,000. Its main span is 455 ft, with a total length of 745 ft. It was designed by Fred G. Michaels and John Suwada, with architecture consulting by William Wells. This bridge is one of the two overcrossings in San Diego County with this unique arch design, the other being the Eastgate Mall Bridge. When traveling northbound on I-15 it is the noticeably high bridge before the SR 76 exit.