ATSSA Traffic Control Supervisor Re Certification Exam 2026

ATSSA TRAFFIC ATSSA Traffic Control Supervisor Re Certification Exam 2026 L=(WS²)/60 for 40MPH or less, L=WS for 45MPH or more - -Formula for Min. taper length The off peak 85th percentile. Which is the speed at or below which 85% of vehicles travel operating speed in free flow conditions - -speed used in formulas should be 125' - -Distance of L for 25 MPH with 12' Lane width 245' - -Distance of L for 35 MPH with 12' Lane width 540' - -Distance of L for 45 MPH with 12' Lane width 660' - -Distance of L for 55 MPH with 12' Lane width 780' - -Distance of L for 65 MPH 12' Lane width L Minimum - -Merging Taper Length 1/2 L Minimum - -Shifting Taper Length 1/3 L Minimum - -Shoulder Taper Length 50'-100' regardless of speed 6 devices 10'-20' apart - -One-Lane, Two-Way Taper (Flagger taper) Length and number of devices 50'-100' per lane - -Downstream taper Length 2L - -Tangent distance (between tapers) 1/2L - -Tangent distance before shifting taper Buffer Space Work Space Traffic Space - -Activity Area Sub-components (3) Recovery Area for errant vehicles: Forgiving design Protects workers and Motorists Always completely empty or clear No vehicles, truck-mounted attenuator, equipment, or materials ATSSA TRAFFIC ATSSA TRAFFIC ATSSA TRAFFIC STRONGLY RECOMMENDED: unless there is a documented reason not to - Longitudinal Buffer Space Where road users are returned to their normal path Extends from the downstream end of the work area to the last device such as end work zone sign May contain: End work zone sign: usually 500' past last device Downstream taper = 50'-100' per lane - -Termination Area is: can contain: (2) 100' - -Recommended Advanced Warning Sign Spaceing: Urban (low speed) 350' - -Recommended Advanced Warning Sign Spaceing: urban (high speed) 500' - -Recommended Advanced Warning Sign Spaceing: Rural 1000', 1500', and 2640' - -Recommended Advanced Warning Sign Spaceing: freeways and expressways (3) 1 Mile 50% Shoulder at beginning of taper if possible, if not, as close to beginning as possible inside taper. - -arrow board visibility distance by design: Night time dimming: Location: Taper: not to exceed distance in feet = to posted speed limit Tangent: distance = double posted speed limit - -device spacing taper: Tangent: A: Low intensity flashing B: High-intensity flashing C: Steady Burn D: 360° steady burn - -Warning lights types: Type A: Type B: Type C: Type D: Uses for portable changeable message sign PCMS - -speed drops significant delays adverse conditions advance notice of closures advance notice of road changes ATSSA TRAFFIC ATSSA TRAFFIC Reinforce static signage Updated guidance information Placed 500'-800' ahead of workzone conflicts or 1.5-2 miles ahead of complex traffic control Uses of screens (mounted on top of rail) - -limit distractions and discourage rubbernecking Reduce headlight glare from oncoming traffic Reduce floodlight glare from night work Should not be mounted where they reduce motirist visibility and sight distance 125' 245' 540' 660' 780' - -Distance of L with 12' Lane Width for: 25, 35, 45, 55, 65 MPH Moved outside the clear zone or be shielded by barrier or crash cushion placed on the shoulder or further from the traveled lane delineated with retroreflective material in a continuous line - -when not in use, where should a PCMS be? portable changeable message sign 1/2 mile visibility day and night - -how far should a PCMS be visible? Portable changeable message sign *M*anual for *A*ssessing *S*afety *H*ardware MASH - -NCHRP 350 rewritten by AASHTO and is now an AASHTO document called what? Temporary Traffic Barriers - -Portable devices designed to prevent penetration by vehicles while minimizing injuries to vehicle occupants. Main function: PROTECTION Secondary function: CHANNELIZATION if not needed for protection then it *SHALL NOT BE USED* Speed, traffic volume / composition, road classification, deflection space, roadway alignment, sight distance, other factors. - -Barrier selection guidelines based on Barrier deflection - -the distance a barrier will displace when struck Portable concrete barriers - -less expensive for long-term projects, easy to maintain, reusable, low deflection. Heavy equipment needed for installation. Concrete, water-filled, anchored, move-able, mobile, steel - -types of temporary traffic barriers ATSSA TRAFFIC ATSSA TRAFFIC Light in color and supplemented with standard delineation or pavement markings - -If Temporary Traffic Barriers are used as channelizing devices they should be: Appropriately flared or protected with properly installed crash cushions - -The blunt end of a barrier is a hazard. *ALL* upstream leading ends shall be: 20:1 - -Typical Flare Rates for Barrier Rail - 70 MPH 18:1 - -Typical Flare Rates for Barrier Rail - 60 MPH Decrease by 2:1 per 5 mph Stopping at 30 mph with 8:1 - -below 60 mph barrier flare rates decrease by The exposed end is outside the clear zone - -extend barrier rail flare until The edge of the *traveled* lane Typically 30' for high-speed facilities - -clear zone is measured from, And is how far Channel Pin and loop (to be phased-out) - -types of barrier connections Stationary non-redirective (inertial) impact attenuators - -sand barrels are an example of what? Re-direct vehicles that impact them - -re-directive impact attenuators do what? Decelerate the vehicle to a stop - -stationary non-redirective Impact Attenuators do what? Minimum of 30" - -Impact Barrels should overlap the fixed object on the traffic side by: Stationing 0+00' - -A conventional way of identifying distances on the plan and on the ground. Located every hundred feet. Cones at least 28" with 2 white retroreflective bands Flaggers properly illuminater Controlled glare Proper apparel (recommended class 3) - -nighttime checklist 60" - -proper width for pedestrian pathway: Provide a 60"x60" passing area for wheelchairs every 200' - -When it is not possible to maintain proper pathway width provide what? ATSSA TRAFFIC temporary traffic barriers - -If significant threat of vehicle incursions into temporary pedestrian pathways _________ should be installed. 2 or 3 - -All workers, including emergency responders, within the right-of-way who are exposed either to traffic (vehicles using the highway for purposes of travel) or to work vehicles and construction equipment within the TTC zone shall wear high-visibility safety apparel that meets the Performance Class ___ or ___. ATSSA TRAFFIC