How to Cone Off and Taper an Aerial Lift Work Zone
A recent incident on December 13, 2016, made news when a local resident captured a video of improper work zone marking performed by utility workers. Comcast employees failed to properly alert and steer drivers clear of the aerial lift work zone and consider the slippery road conditions, causing a few slide-offs and one minor collision.
Clear visibility of equipment and the designated work zone, as well as other specific safety protocols, needs to be established by aerial lift workers to minimize hazards and prevent accidents like the recent news story from happening.
Divide the Temporary Traffic Control
When marking a work area, it is important to know of the different zones to cone off to provide plenty of advance warning to drivers. The TTC (temporary traffic control) can be broken down into four main sections: the advance warning area, the transition area, the activity area, and the termination area.
The Advance Warning Area
The advance warning area is the section of highway or road where drivers are notified of the upcoming work or incident. On urban streets, the placement of the advance warning should range from 4 to 8 times the speed limit in mph. For rural highways, the range is between 8 to 12 times the speed limit in mph.
The Transition Area
The transition area is the area of road where drivers are redirected out of their normal path. It usually consists of the strategic use of tapers, which are sections of channeling devices like cones.
The Activity Area
The activity area is the section of highway or road where the work activity is taking place and is usually marked off by cones to redirect drivers. The work activity area is closed to road users and is used for workers and equipment like aerial lifts.
The Termination Area
The termination area is the section of road where drivers are returned to their normal driving path. It extends downstream to the “End Road Work” sign.
The Correct Use of Tapers in Road Work
A taper is the length of channeling devices that is used to redirect road users to a different path. It is important for workers to understand how to position them properly.
The correct way to determine the appropriate taper length is as follows:
- 40 mph or less: the taper length in feet = WS2=/60
- 45 mph or more: the taper length in feet = WS
- W = width of the offset in feet
- S = posted speed limit
Each type of work zone taper length is determined by this chart:
- Merging Taper, before the transition section to allow drivers to adjust their speeds—at least the length of the taper in feet
- Shifting Taper, when a lateral shift is needed—at least half of the taper length in feet
- Shoulder Taper, on a high-speed road where shoulders are part of the activity area—at least a third of the taper length in feet
- One-Lane, Two-Way Traffic Taper, used before the activity area—at least 50 feet, and no more than 100 feet
- Downstream Taper—at least 50 feet, and no more than 100 feet
Follow the proper temporary traffic control protocols and ensure all workers are trained in aerial lift certification to further prevent accidents from happening.