(Portland, OR) -- Portland Bureau of Transportation officials say they're working to make streets safer as wintry weather rolls back over the area. PBOT says that will include the distribution of 100 tons of rock salt along North Going Street, Southwest Terwilliger Boulevard, and Southeast 112th Avenue. Officials say it will be the largest use of salt in Portland's modern history. The agency says it will also expand its plow routes to 340 more lane miles that are school bus routes.