Employees of Traffic & Lighting Systems of Tulsa install traffic sensors Wednesday at York and Gibson streets. The project is one of two that could tie up traffic today and Thursday. Morris Baxter Jr., traffic foreman, said the installation of traffic loops would begin at York and Gibson streets and then move south to York and Chandler Road. Lanes will be closed while the traffic signal sensors are being installed and re-opened immediately thereafter. Baxter urged motorists to exercise caution while driving through the work zones.