APM: 31 Location: Market St and 10th St, Colusa Reassurance shield as 45 joins 20. APM: 31 Location: Market St and 6th St, Colusa Reassurance shield omitting SR 45 as we pass through downtown Colusa. APM: 31 Location: Market St and Bridge St, Colusa A few blocks later, both 20 and 45 turn to follow the east edge … Continue reading California State Route 20, SR 45 to SR 45