Grass Valley is notifying drivers of a couple routes that will be impacted by workers over the next day. The traffic signal at the intersection of East Main and South Auburn streets will be non-operational for replacement of a traffic signal pole from 7 p.m. to midnight today. The traffic control system at East Main and South Auburn streets should allow public traffic to pass without delay the majority of the time that the work is in progress, the city said in a statement. Any delays should be minimal to the traveling public, as every effort will be made to …