A grass fire stopped traffic along State Route 78 between Rancho Sante Fe Road and San Marcos Boulevard.
The fire, first reported around 12:21 p.m., was burning along the highway shoulder.
The blowing smoke caused a traffic backup stretching west to Rancho Sante Fe Drive according to SigAlert.com.
The California Highway Patrol told NBC 7 San Diego the fire was smoke only and that its units were working to clear the area.
