A work zone or temporary traffic control zone generally has five sections:
Work zones or road construction zones are dangerous not just for motorists but also for the workers. Some common accidental hazards for construction or maintenance worker include -
Flagging protects the work crew and offers guidance and direction to the traffic. In work zones, flaggers are required to maintain continuous traffic flow at safe speeds, especially when only one lane is available for traffic to funnel from two directions. Drivers should be warned in advance with Flagger signs that there will be a flagger ahead.
Flaggers must use STOP/SLOW paddles, paddles with lights, or flags. They also need to be dressed in high-visibility safety apparel that meets ANSI/ISEA Class 2 or 3 requirements, that ensure they are visible from a minimum distance of 1,000 feet.Flaggers also use hand signals and it’s important to be familiar with them.
When a flagger’s paddle says “STOP,” slow down to a stop until further instruction from the flagger comes. In a construction zone that has only one lane to use, flaggers will allow one lane of traffic to flow at a time.
When it is okay and safe to proceed, the flagger will flip their paddle around to “SLOW.” A wave of the arm shows that it is safe for you to proceed at a slow speed.
If the flagger indicates you to slow down with the paddle turned to “SLOW,” and with an up and down hand gesture, it means you need to drive at a slow speed in the work zone
The OSHA standard that regulates work zone safety is 29 CFR 1926 Subpart G (Signs, Signals, and Barricades) which clearly mentions that:
There are 28 OSHA-approved State Plans, operating state-wide occupational safety and health programs. State Plans are required to have standards and enforcement programs that are at least as effective as OSHA's and may have different or more stringent requirements.
Traffic control devices signal that a work zone is ahead. These devices tell drivers where they are, where they are going and how to get there. Traffic control devices communicate their message in several ways, by color, shape, words, symbols and placement to provide information. Following traffic control devices can be used to ensure road work safety -
In transition areas, more robust vehicle-mounted traffic control devices may be used, such as arrow boards, portable changeable message signs, and high-intensity rotating, flashing, oscillating, or strobe lights, instead of channelizing devices.
MUTCD Chapter 6 provides a table that can be referred to to calculate how ahead a road construction sign or road work sign must be installed from transition or point of restriction.
The first work zone sign or advanced warning sign must be placed 100 feet from the road work. Subsequently, the distance between the first and the second sign and the second and the third sign must also be 100 feet on urban roads where vehicles run at low speed. (The third sign here is the first one in a three-sign series encountered by a driver approaching a traffic control zone.) If the speed limit is set high on these urban roads, these same signs must be placed 350 feet ahead of the road work.
MUTCD Chapter 5 clearly mentions that “Road users should be guided in a clear and positive manner while approaching and within construction, maintenance, and utility work areas.”
Chapter 6 explains how Temporary Traffic Control Zone signs convey both general and specific messages by means of words, symbols, and/or arrows. Following are the requirements/recommendation for road construction signage -
