Enhancing Safety for Road Maintenance Works
A traffic management plan is required to outline the hazards, and specify the measures needed for traffic control to maintain mobility and worker safety.
On the afternoon of Tuesday, 21st November 2017, two workers involved in marking lanes between Safari Park and Homeland hotels along Thika Road (A2 Highway) in Nairobi died after a being knocked down by a car. Whereas the main cause of the accident was not reported, it is likely that the accident could have been avoided if the road works were properly secured and proper signage put in place.
Highway maintenance work has many unsafe factors that include large traffic volume, high speed, pavement under heavy load and potential danger caused by bad weather on the maintenance personnel. There is therefore need for agencies involved in such works to conduct detailed risk assessments in order to ensure the safety of the workers and other road users.
A traffic management plan is required to outline the traffic hazards, and specify the measures needed for traffic control. A traffic management plan can be defined as: "the strategies designed to safely mitigate the impact of construction, rehabilitation, maintenance, incident management and special events on roadways to maintain mobility and worker safety."
Traffic control measures must be selected and implemented with the drivers' perspective in mind. Traffic control devices (cones and barrels) should be used to define the closed portion of the roadway that is the work zone. Even short-term operations can realize a safety benefit from placing cones in a manner that sends an obvious message to drivers that a portion of the road is closed and they must divert around the work zone. Such devices should be placed in such that they maintain adequate sight distance for driver recognition and reaction on straight highway sections if possible.
Roadworks site signage needs to be consistent with the actual conditions on the site. Once road users know that they can trust the signage at a roadworks site, they will be more likely to obey speed limits, and behave more consistently at the end to the site.
Construction cones are the most common safety equipment used to warn road users of ongoing road works. The cones are typically painted fluorescent 'safety' orange because it is the easiest color to distinguish from the color of the sky. They also tend to have reflective striping on them to increase visibility during the night.
It is recommended that cones should be at least 18 inches tall for normal situations. For high speed, or high volume operations they must be 28 inches tall minimum.
For cones to be effective, they need to be regularly checked to ensure they are in good condition, not faded and have a good night time visibility if necessary. They should also be placed in a way that they are not obscured by vegetation, vehicles, plant or other devices and are displayed in correct sequence. It is however unfortunate that in many cases, worn out cones, some covered with dirt that obscures their visibility are used to secure road works.
Other channelization devices that can be used to direct traffic away from or around a work area, or to separate two-way traffic include;
- Traffic Safety Drums - used on highways due to greater target value and imposing size.
- Barricades - They protect spot hazards and close roadways and sidewalks with appropriate signing. Barricades can also be used to provide additional protection to work areas.
- Temporary Pavement Markings - These markings delineate lanes and tapers on long-term projects. If it is necessary to divert traffic across existing pavement markings, the channelizing device used must be so dominant that a motorist's attention is drawn completely away from the existing marking. Reduced device spacing is recommended.
- High Level Warning Devices - They are tall, portable stands with flags or flashing lights visible above traffic. Used with flags only, they may have a sign or flashing light attached, or be attached to vehicles used in moving or mobile work operations.
- Temporary Barriers - There are several types of barrier protection used in work zones: concrete barrier, movable concrete barrier, steel barrier and water-filled barrier. While barriers are effective and provide positive protection to work operations, they may result in more damage to an impacting vehicle.
- Lighting Devices - Use to call attention to hazardous situations, especially at night. Includes warning lights, flashing vehicle lights, floodlights, and flashing arrow boards.
Hand Signaling Devices / Flagging should only be used when other methods of traffic control are inadequate and should be done by well-trained individuals. The effectiveness of flagging is diminished at night as the flagger may not be visible to the motorist therefore where possible, efforts should be made to control traffic by other means.
When used, the flagger should be located within a coned area (usually the shoulder or other relatively safe location) but not within the taper itself. As with other workers in night work zones, flaggers must wear traffic vests made of highly visible materials supplemented with reflective material visible on all sides of the wearer and a highly visible hard hat with reflective qualities.
In summary, road maintenance operations require employees to be on the alert to protect themselves, fellow crew members and the traveling public. Performing jobs safely is a priority and an integral part of maintenance operations. Employees must therefore be trained to know the rules, policies and practices intended to promote a safe work environment.
In addition, every employee needs to develop the habit of thinking safety before and during the work to be done. A positive attitude toward safety will not only help to protect the employee from injury, but will also lead to continued job satisfaction.