A Guidebook for Nighttime Construction: Impacts on Safety, Quality, and Productivity (2012)

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72 Most STAs have adapted work-zone safety standards based on the Manual on Uniform Traffic Control Devices for Streets and Highways (MUTCD) (FHWA 2009) and other FHWA guidance. These standards and guidelines provide a current state of practices and procedures to promote safety and mobility during construction and maintenance operations. The guidelines should be considered carefully and applied under the special conditions of nighttime work. Resource Manual on Uniform Traffic Control Devices for Streets and Highways (MUTCD) http://mutcd.fhwa.dot.gov/ http://mutcd.fhwa.dot.gov/pdfs/2009/mutcd2009edition.pdf NCHRP has undertaken studies and published reports specifically addressing nighttime con- struction activity. Two very important NCHRP reports on nighttime construction that address safety and work zones were produced by James E. Bryden and Douglas J. Mace in 2002; these are NCHRP Report 475: A Procedure for Assessing and Planning Nighttime Highway Construction and Maintenance (2002a), and NCHRP Report 476: Guidelines for Design and Operation of Nighttime Traffic Control for Highway Maintenance and Construction (2002b). Introduction Nighttime project work activities present a distinct set of hazards to both construction work- ers and the traveling public. Because of the reduced visibility commonly associated with night- time work zones and possible driver impairment at night, the safety of construction personnel and the traveling public must be addressed in a very proactive manner. The significant hazards imposed by nighttime construction activities are attributed to the following (Arditi et al. 2004): • Decreased visibility. • Glare from work-zone lighting and vehicles passing through the work zone. • Higher vehicle speeds. • Driver impairment by alcohol, drugs, or fatigue. • Driver confusion. • Vision reduction of older drivers. These factors lead to higher nighttime work-zone fatalities compared to daytime work-zone rates (Arditi et al. 2004). Numerous studies have been conducted to determine accident causes and ways to prevent both worker accidents and traveling public accidents within the work zone. C H A P T E R 8 Safety

Safety 73 While 53 worker fatalities in twilight or nighttime highway work zones were caused by traffic for the period 1992 to 2000, 17 worker fatalities were caused exclusively by the construction work for the same period (Bureau of Labor Statistics). Roughly 76 percent of the twilight/nighttime highway work-zone fatalities were traffic-related with 53 percent due to vehicles entering the work area, 13 percent due to impaired drivers, and 10 percent due to workers stepping into traffic. Therefore, traffic through nighttime work zones clearly poses a significant hazard to the workforce. Key Take-Away Planning for safe night construction needs to address both construction operations and traffic through the work zone. Important work-zone enhancements that improve nighttime construction safety are as follows (Bryden 2004): • Good temporary lighting. • Brighter signs. • Larger signs. • More signs. • Positive guidance. • More safety devices. • Driver information—such as clear driver guidance. • Law enforcement support. • Worker visibility and training. Resource Behavior Study of Merge Practices for Drivers at Work Zone Closures http://www.intrans.iastate.edu/research/detail.cfm?projectID=147399822 Safety Precautions Many safety actions during construction are the same for daytime and nighttime construction activities. Table 8.1 indicates the factors needed to prevent the root causes of construction acci- dents (Toole 2002). These root causes and preventive actions are applicable to both daytime and nighttime construction. However, for nighttime construction, the emphasis on safety needs to be increased. Lighting to Enhance Safety During nighttime construction, proper and adequate lighting is required both to ensure con- struction quality and to reduce the likelihood of accidents. Adequate lighting helps workers perform work tasks in a productive and safe manner. Lighting must also be established so it does not create glare for motorists entering the work zone and, therefore, create an unsafe condition for the traveling public. High-mast lighting, instead of portable lights, is recommended during all phases of nighttime project work. The most common non-glare lighting equipment for nighttime construction is the balloon light. To achieve a safe work zone, lighting plans should be developed and carefully reviewed to minimize glare.

74 A Guidebook for Nighttime Construction: Impacts on Safety, Quality, and Productivity Nighttime construction lighting should follow standard or special provisions imposed by local governments or by the Occupational Safety and Health Administration (OSHA). Generally, different types of construction activity require certain levels of illumination to ensure adequate lighting for the tasks. The three categories of nighttime construction illumination levels are detailed in Table 8.2 (Ellis et al. 2003). Keep in mind when reviewing Table 8.2, fixed roadway lighting typically emits less than 20 lux. Root Cause of Accident Preventive Actions Lack of proper training • Provide task-specific safety training • Test knowledge or observe employee • Provide access to training records Deficient enforcement of safety • Monitor work on frequent basis • Know safety requirements for task • Enforce safety Safety equipment not provided • Provide proper safety equipment for the task • Enforce use of equipment • Inspect and maintain safety equipment Unsafe methods/sequencing of construction tasks • Establish proper methods • Establish proper task sequencing • Control methods and sequencing Unsafe site conditions • Establish a clean and uncluttered work-site culture • Observe site conditions regularly • Control site conditions Failure to use proper safety equipment • Observe employees performing task constantly • Influence behavior through: − Evaluations − Training − Incentives Poor attitude toward safety • Observe and interact with workers frequently • Influence attitude through: − Evaluations − Training − Incentives Sudden deviation from prescribed behavior • Evaluate employees’ emotional condition daily • Evaluate physical condition daily Table 8.1. Factors needed to prevent root causes of construction accidents (Toole 2002). Category Illumination (lx) Heights of Candles Recommended For Sample Activities I 54 lx 5 ft General illumination of activity areas; mainly for visibility in the area where crews are working • Excavation • Embankment • Landscaping II 108 lx 10 ft Illumination on and around the construction equipment; use for seeing tasks • Resurfacing • Paving • Bridge decks III 216 lx 20 ft Tasks that present high visual difficulty requiring close attention by workers • Mechanical • Electrical • Detail work Note: lx is the symbol for lux, the SI unit of illuminance. Table 8.2. Summary of illumination guidelines by activity (Ellis et al. 2003).

Safety 75 Higher illumination levels are recommended for activities that require higher levels of dis- cernibility, such as electrical work. A lower illumination level is recommended for activities like excavation. Further information on nighttime illumination guidelines is available in Chapter 3, Illumination. Nighttime Visibility and Retroreflectivity An important aspect of nighttime construction safety is worker visibility and retroreflectivity of signing. The requirement to be visible is vital for the safety of the workers. Retroreflectivity, or retroreflection, can be defined as a ratio of the amount of light returned from a traffic sign versus the amount hitting the traffic sign. It is a way of measuring the efficiency of the material used to surface traffic signs. According to the American National Standards Institute/International Safety Equipment Association (2006), accidents are prevented when the workers in the work-zone area are visible and can be easily detected by equipment operators and motorists. Therefore, it is essential for transportation agency personnel and construction workers to use safety equipment and that traffic signs and devices be highly visible and retroreflective. Tip Be sure that all protective clothing (i.e., vest) complies with latest ANSI II-III requirements. Retroreflectivity of Traffic Signs Maintaining retroreflectivity of traffic signs is crucial to providing safe guidance to nighttime traffic through the work zone. The MUTCD specifies different methods of inspection that are necessary: visual inspection method by using the comparison panel procedure, calibrated sign procedure, and consistent parameter procedure and a retroreflectivity measurement method, through measurements made with hand-held devices. Traffic control devices, including traffic barrels and cones, must also have clean reflective strips to guide motorists. The MUTCD has guidance concerning maintaining traffic signs at a minimum level of reflec- tivity. It also includes guidance concerning setup and maintenance of signs. Figure 8.1 provides some of the language in the MUTCD on minimum retroreflectivity. Tips • The objective is to ensure that signs and channelizing devices are in good condition, visible, and retroreflective for the traveling public. • Signs and all devices must be kept clean. Tips • Change vehicle and equipment paint to attention-grabbing colors. • Add retroreflective tape to construction vehicles and equipment. High-Visibility Personal Protective Equipment OSHA standard 29 CFR 1926.28(a), Safety and Health Regulations for Construction, explic- itly states the employer is responsible for requiring that workers wear the appropriate personal protective equipment (PPE) in all operations where an exposure to hazardous conditions exists or where the standard indicates the need for using such equipment.

76 A Guidebook for Nighttime Construction: Impacts on Safety, Quality, and Productivity Key Take-Away Proper clothing is considered the most important element to ensure worker safety. High-visibility PPE protects workers from potential construction hazards and helps in recog- nizing workers in decreased light situations. All personnel—whether contractor or agency—in a nighttime work zone must wear highly visible outer garments. High-visibility safety garments must be worn at all times. The MUTCD outlines the standards for high-visibility clothing explicitly. The garments must be retroreflective and visible from a minimum distance of 300 m or 1,000 ft. The categories of available high-visibility PPE and examples are listed in Table 8.3. Safety garments are normally made in accordance with several industry standards worldwide: • British Standard Protective Clothing—High-Visibility Clothing BS EN 471:1994. • European Standard Retroreflective Materials and Devices for Road Traffic Control Purposes AS/NZS 1906.4 (1997). • Canadian Standard of High-Visibility Safety Apparel CAN/CSA Z96-02. Resources ANSI/ISEA 107-2004 MADE EASY: A Quick Reference to High-Visibility Safety Apparel. 3M. Occupational Health and Environmental Safety Division. 2005. http://mws9.3m.com/mws/ mediawebserver.dyn?6666660Zjcf6lVs6EVs666NA8COrrrrQ-. Type Examples Safety vests Regular safety vests and self-illuminating safety vests Safety shirts Long sleeves, short sleeves, winter shirts, and T-shirts Safety pants Long pants (trousers) and short pants Headgear Hard hats, caps, winter hats, hard hats, high-visibility cover Outerwear Coats, rain suits, windbreakers, coveralls/ jumpsuits Accessories Retroreflective strips, ankle and hand bands, high-visibility gloves, sash belts, batons, and flashers Table 8.3. High-visibility personal protection equipment types and examples (Abraham et al. 2007). Section 2A.08 Maintaining Minimum Retroreflectivity Support: 01 Retroreflectivity is one of several factors associated with maintaining nighttime sign visibility. (see Section 2A.22). Section 2A.22 Maintenance Guidance: 01 Maintenance activities should consider proper position; cleanliness, legibility, and daytime and nighttime visibility (see Section 2A.09). Damaged or deteriorated signs, gates, or object markers should be replaced. 02 To assure adequate maintenance, a schedule for inspecting (both day and night), cleaning, and replacing signs, gates, and object markers should be established. Employees of highway, law enforcement, and other public agencies whose duties require that they travel on the roadways should be encouraged to report any damaged, deteriorated, or obscured signs, gates, or object markers at the first opportunity. 03 Steps should be taken to see that weeds, trees, shrubbery, and construction, maintenance, and utility materials and equipment do not obscure the face of any sign or object marker. 04 A regular schedule of replacement of lighting elements for illuminated signs should be maintained. Figure 8.1. MUTCD language on minimum reflectivity (FHWA 2009).

Safety 77 ANSI/ISEA 207-2006: American National Standard for High-Visibility Public Safety Vests. 3M. Occupational Health and Environmental Safety Division. 2008. http://multimedia.3m.com/ mws/mediawebserver?mwsId=SSSSSu7zK1fslxtUnxmUmY_eev7qe17zHvTSevTSeSSSSSS— &fn=What%20is%20ANSI%20207%20Standard.pdf. In the U.S., the use and design of high-visibility safety garments falls under the responsibility of the International Safety Equipment Association (ISEA) in collaboration with the American National Standards Institute (ANSI). The ANSI/ISEA published standards establish different performance criteria for the design and use of safety apparel. According to ANSI, high-visibility safety garments are PPE intended to provide conspicuity during both daytime and nighttime use. Conspicuity may be increased if high contrast is pro- vided between the garment and the environment against which it is seen. High-visibility safety garments are categorized into four different performance classes, as shown in Table 8.4. These four performance classes are further recommended for different types of working con- ditions, as shown in Table 8.5. Different work-zone conditions—traffic speed, volume of activity, minimum area of background/retroreflective material—set the performance class. The MUTCD specifically requires all workers within the right-of-way or work zone to wear high-visibility apparel. The workers include traffic personnel and uniformed law enforcement officers. Figure 8.2 provides the language of the safety apparel portion of the MUTCD. Considerations The MUTCD includes a specific high-visibility apparel recommendation for flaggers. Night- time flaggers should wear high-visibility safety apparel that meets the Performance Class 3 requirements of ANSI/ISEA 107–2004 (FHWA 2009). The apparel background (outer) material color shall be fluorescent orange-red, fluorescent yellow-green, or a combination of the two as defined in the ANSI standard. The retroreflective material shall be orange, yellow, white, silver, yellow-green, or a fluorescent version of these colors, and shall be visible at a minimum distance of 1,000 ft. The retroreflective safety apparel shall be designed to clearly identify the wearer as a person. Performance Class Description 1 Provides the minimum amount of required material to differentiate the wearer from the work environment 2 Superior visibility for wearers by the additional covers of the torso and is more conspicuous than Class 1 3 Greater visibility to the wearer on both complex backgrounds and through a full range of body movements by placing retroreflective material on the arm and/or leg 4 Waistband trousers and shorts that meet all the requirements for the retroreflective and background material in performance Classes 1, 2, and 3 Table 8.4. High-visibility safety garments by performance class (Abraham et al. 2007, originally from ANSI/ISEA 2004). Conditions Performance Class 1 2 3 Speed of traffic 25 mph 25–50 mph Above 50 mph Volume of activity Low Medium High Minimum area of background/ retroreflective material 217 sq in./ 155 sq in. 775 sq in./ 201 sq in. 1,240 sq in./ 310 sq in. Table 8.5. Working conditions for which a performance class is applicable (Sant 2001).

78 A Guidebook for Nighttime Construction: Impacts on Safety, Quality, and Productivity Several research studies have shown that yellow is the most recognizable color during daytime, but orange is better at dusk and during the nighttime. Tip Blaze orange was found to be the most conspicuous of the retroreflective trim colors (Abraham et al. 2007). STA officials interviewed for this guide recommended construction workers wear hardhats, reflective strips, and vests; and full suits and gloves when workers are establishing lane closures. Two-piece safety apparel tends to provide better visibility of workers when they bend over to perform a construction activity (Cottrell 1997). This apparel is recommended by the industry as a response to the Minnesota DOT (Mn/DOT) request to develop higher-visibility safety apparel. At present, Mn/DOT requires all workers to wear high-visibility vests, caps, and pants to increase worker visibility in construction work zones at all times (Mn/DOT 1997). The National Institute of Occupational Safety and Health (NIOSH) recommends the use of arm and knee bands to enhance visibility, as well as strobe lights on worker vests for better identification of the workers. However, the performance of safety vests in nighttime conditions is dependent on both the characteristics of the vests (amount of retroreflective material and design of the vest) and the characteristics of the construction/maintenance sites (weather, lighting, and traffic volume) (Arditi et al. 2004). Safety Management for Nighttime Construction Construction work zones can create unique safety hazards depending on heavy equipment, materials, and construction activities. The perception is that nighttime construction work exposes the worker and the traveling public to higher risk and severity of work-zone accidents. Many types of hazards are associated with nighttime work, and it is crucial for agencies and contractors to ensure that proper safety measures are exercised. Standard: 04 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 Temporary Traffic Control (TTC) zone shall wear high- visibility safety apparel that meets the Performance Class 2 or 3 requirements of the ANSI/ISEA 107–2004 publication entitled “American National Standard for High-Visibility Safety Apparel and Headwear” (see Section 1A.11), or equivalent revisions, and labeled as meeting the ANSI 107-2004 standard performance for Class 2 or 3 risk exposure, except as provided in Paragraph 5. A person designated by the employer to be responsible for worker safety shall make the selection of the appropriate class of garment. Option: 05 Emergency and incident responders and law enforcement personnel within the TTC zone may wear high-visibility safety apparel that meets the performance requirements of the ANSI/ISEA 207-2006 publication entitled “American National Standard for High-Visibility Public Safety Vests” (see Section 1A.11), or equivalent revisions, and labeled as ANSI 207- 2006, in lieu of ANSI/ISEA 107-2004 apparel. Standard: 06 When uniformed law enforcement personnel are used to direct traffic, to investigate crashes, or to handle lane closures, obstructed roadways, and disasters, high-visibility safety apparel as described in this Section shall be worn by the law enforcement personnel. Figure 8.2. Language on safety apparel requirement in MUTCD Section 6D.03, Worker Safety (FHWA 2009).

Safety 79 Construction and maintenance workers should be instructed about the distinctive risks and hazards imposed by nighttime construction. Poor visibility, reduced lighting, worker fatigue, and driver drowsiness and substance abuse are all accident risk factors when a project is constructed at night. Extra proactive safety measures are, therefore, essential for safe nighttime construction, spe- cifically in the work zone. The safety implications should always be considered, even when the work zone has a very short duration, occupies a very short length, or is located on the shoulder or even beyond the traffic lane. Transportation agencies and contractors should have proactive safety plans. These safety plans should include the employer’s specific policies, guidelines, and practices, which employees are expected to follow to create a safe work environment. Many agencies within the construction industry, including the Associated General Contrac- tors of America (AGC), the Associated Builders and Contractors (ABC), and the Construction Industry Institute (CII), have produced guideline information for safety management. More than 170 safety improvement techniques are listed within the CII’s Zero Injury Tech- niques (1993) document. This research team recommends that transportation officials and con- tractors review these techniques and, as appropriate, incorporate them in their safety plans for nighttime work. Tip Safety management plans need to be updated and modified regularly based on experiences from past projects, as well as with any project design changes. Tips Top five effective ways to manage site safety are as follows (Liska et al. 1993): • Pre-project planning for safety. • Safety orientation and training. • Written safety incentive programs. • Accident/incident investigations. • Alcohol and substance abuse program. Safety Talks Safety talks are a good way to discuss and disseminate vital information pertaining to night- time construction safety issues. Talks can be part of meeting agendas or conducted separately. Safety talks are usually conducted ad-hoc, prior to the start of any work, and they provide a good time to evaluate employee emotional and physical condition. Safety talks can also be regularly-scheduled, such as daily or weekly. Safety talks during January through April can be used to warn workers about cold-weather seasonal hazards or, in summer months, about possible extreme weather conditions (thunderstorms or heat). Key Take-Away Effective communications are the key to addressing nighttime construction safety issues effec- tively. Safety talks about nighttime construction issues, such as traffic and the causes of crashes, help everyone understand the hazards and what to do in case of an accident.

80 A Guidebook for Nighttime Construction: Impacts on Safety, Quality, and Productivity Key Take-Away Toolbox talks are short discussions or presentations by supervisors with their crews. Tip Daily toolbox safety meetings are used to target hazards of tasks and to emphasize activities that will take place during the work period. Such talks usually focus on a specific topic. Key Take-Away Toolbox talks help workers recall their knowledge on safety and, therefore, increase worker safety. Toward the end of the year, the safety talk sessions may recap the safety encounters experi- enced throughout the year. The recommendation is to provide adequate information on differ- ent topics associated with general safety, together with instructions on specific tasks. Discussions should include recognition of the need to avoid situations involving the risk, behavior of the road worker toward the traffic, considerations before commencing and during the work, as well as the procedures to follow in case of incidents. A sample safety talk conducted by the NYSDOT includes the importance of being visible at all times by wearing high-visibility apparel, PPE, construction vehicle protection, and maintenance of traffic signs and guiding devices. Resource NYSDOT Nighttime Construction Safety Tailgate Safety Talks can be found at: https://www. nysdot.gov/main/business-center/contractors/construction-division/safety-health-information/ tailgate-safety-talks. Tip Be creative and try to conduct interactive safety talk sessions. Encourage workers to exchange thoughts on safety issues, or conduct a written quiz about the topics discussed. (See the Appendix for a sample safety quiz.) Safety Inspections Safety inspections of nighttime traffic control procedures and safety devices should be per- formed regularly. Safety inspectors may need to be made more aware of the need for good lighting and should inspect lighting constantly. Tip Monitoring nighttime traffic can provide data to support planning of future nighttime work. Contractors should be encouraged to conduct their own safety inspections of vehicles and heavy equipment with attention to lights and backup alarms; work-zone operations; traffic con- trol devices; and signing, markings, signals, traffic systems, and roadway safety appurtenances. Safety Training and Safety Awareness Programs Because night workplaces can add demands on workers and can expose them to greater risks than daytime work, additional training is needed to ensure that workers are prepared to meet

Safety 81 the added demands. All workers on night projects need to be made aware of the special risks inherent in night work, along with the safeguards and procedures to be followed on the project to compensate for these risks (Bryden and Mace 2002b). Key Take-Away Safety training should begin as soon as workers are hired and it is likely the responsibility of the contractor to ensure that workers are given sufficient safety training, but the STA should monitor or even require this training. Nighttime work-safety training includes, but is not limited to, the following topics: • Safety rules. • Worksite policies. • Safety apparel and general work clothing requirements. • Being alert for vehicles entering the work zone. • Procedures for backing vehicles. • Awareness of backing vehicles. • Designated parking locations. • Walkways and crossing points to safely access the worksite. • Drivers and equipment operators alert for workers on foot at night. • Specific site hazards (e.g., overhead utilities are very difficult to see at night). Tip All workers who complete safety training programs should also be asked to provide written evaluations to determine whether or not they fully understood the training material. Safety training materials can be produced and distributed to workers in different forms, such as booklets, manuals, digital file storage (CDs and flash drives), charts, and others. Figure 8.3 Figure 8.3. Safety training CD by the FHWA.

82 A Guidebook for Nighttime Construction: Impacts on Safety, Quality, and Productivity illustrates an example of a safety training program offered by the National Work Zone Safety Information Clearinghouse. A webinar session at www.workzonesafety.org/video_viewer.php?id=99c2a7a9-95b9-4642- a80a-e80516d8b652&width=990&height589 takes viewers on a virtual tour of this Roadway Safety+ training program. The program has modules on temporary traffic control (TTC) design and in-depth training on night work. More information can be found at www.workzonesafety. org/node/9748 or by contacting the American Road & Transportation Builders Association in Washington, D.C. In the case of nighttime work, under the subject of PPE, it is essential to provide workers with the following knowledge on high-visibility apparel: • When to use the high-visibility apparel. • Fitting instructions, including how to put on and take off the apparel. • Importance of using the apparel properly. • Limitations of use. • How to store and maintain the apparel. • How to check for serviceability. • How to clean or decontaminate the apparel correctly, with complete washing and/or dry cleaning instructions. Once workers complete the safety training, it is still necessary to repeat critical ideas during toolbox safety talks. Toolbox safety talks provide an opportunity for supervisors and manage- ment to observe if workers are wearing the appropriate safety apparel. Many organizations and agencies conduct safety awareness programs in other languages, such as Spanish to accommodate a Hispanic construction workforce. According to OSHA’s training standards policy statement, if an employee does not speak or comprehend English, it is the responsibility of the employer to provide instruction in a language the employee can understand. Likewise, if the employee’s vocabulary is limited, training must be provided to account for that limitation. Employers must inform and train workers in a language they can understand. The importance of providing multilingual safety training cannot be overemphasized. For safety and in case of emergencies, the FHWA stresses the importance for personnel in the transportation industry to know some basic words in other languages. Therefore, a pamphlet is available to ensure, when it comes to safety issues, everyone may have some basic knowledge of Spanish. Figure 8.4 shows the cover of this two-page pamphlet published by the FHWA. The pamphlet is available at www.workzonesafety.org/files/documents/public_awareness/WZCH- spanishbrochure.pdf. In addition to safety training, agencies can use other initiatives to promote safety. These include safety awareness programs, awards, and recognitions. As part of the Road Construction Industry Consortium Awareness Program, the Laborers Health & Safety Fund of North America has published a Roadway Safety+ Awareness Program Night Work Trainee Booklet. It is a simple but excellent reference (see Figure 8.5). This booklet covers night work hazards and offers information about specific protections nec- essary when working at night. It includes tips on how to minimize sleep loss: maintain a strict sleep schedule, make sleep a priority, and, during the night, eat small protein-rich meals and avoid fats and sugars. The booklet is available at http://www.workzonesafety.org/files/documents/ training/courses_programs/rsa_program/RoadwaySafety_Booklets_English/RoadwaySafety_ Booklet_NightWork_English.pdf.

Safety 83 Figure 8.4. FHWA pamphlet of basic Spanish for safety and emergencies. Tips Tips for safety training with a bilingual workforce (Business and Legal Resources 2011): • Establish bilingual companywide safety training. • Hire supervisors who are bilingual. • Provide signage (safety guidelines, emergency evacuation, warnings) in the languages spoken by the employees and include diagrams or symbols. • Pair new employees with bilingual veteran employees who understand and comply with safety and health guidelines. • Conduct periodic jobsite visits and work with employees in the field. • Follow up formal training with demonstrations, and have employees demonstrate to one another. • Conduct safety meetings and toolbox talks to reinforce formal training. The Iowa DOT has a Safety Calendar it uses to spread the safety message. Each page above the monthly calendar contains information on safety issues and safety checklists. This calendar presents basic yet valuable information, acts as a simple communications tool, and serves as a reminder to employees about construction safety. Figure 8.6 provides excerpts from the Safety Calendar.

84 A Guidebook for Nighttime Construction: Impacts on Safety, Quality, and Productivity Figure 8.5. FHWA Roadway Safety Awareness Program booklet. Figure 8.6. Safety Calendar used by the Iowa DOT.

Safety 85 Best Practices for Nighttime Work-Zone Operations Several methods can be used to provide safe nighttime work zones. Work-zone traffic safety can be improved through good engineering and design practices, enforcement of traffic laws and regulations, and agency procedures. To ensure that effective work-zone traffic management is implemented, a comprehensive traffic control plan (TCP) that considers the nature of nighttime conditions should be devel- oped for the work-zone area. Development of a proper TCP is extremely important prior to beginning work. Key Take-Away The key purpose of a TCP is to offer safe and effective movement of road users within the TCP zones to protect road users, workers, responders to traffic incidents, and equipment. The TCP should consist of information pertaining to the safety of motorists, bicyclists, pedestrians, workers, enforcement/emergency officials, and equipment. Engineering and Design Practices Other ideas to improve nighttime work zones include the following: • Design and installation of TTC devices (Oregon DOT 2009). Nighttime work zones frequently present higher risk for the traveling public if proper precau- tions are not exercised. The TTC devices used to deliver information to motorists and to alert them to the presence of nighttime workers and potential roadway threats need to be noticeable and reliable (see Figure 8.7). Visibility of flaggers and their vehicles is required for the security and safety of both workers and the traveling public. It is essential that devices are set up properly and within the spacing recommended in the MUTCD. In addition, the device should comply with state and local regulations and standards. • Use of intelligent transportation systems (ITS) for work zones. The MUTCD recommends the use of ITS for improvement of the work zone in terms of work-zone traffic and control systems (see Figure 8.8). The ITS tools include portable changeable message signs to display delay or speed information ahead of the work zone. Enforcement of Traffic Laws and Regulations Tip The use of law enforcement personnel can help to reduce the speed of motorists entering nighttime work zones. Agency Procedures Work Vehicles For work vehicle protection, warning lights with 360 degree visibility should be required; two lights are better for depth perception and amber is the preferred color. Rotating/flashing incan- descent lights are best; strobe lights are not as good. Supplement vehicle warning lights with four-way flashers and retroreflective marking. Night Flagging Night flagging is very dangerous. Where flagging must be used, the flagger position must be well lit and the flagger must wear proper retroreflective clothing.

86 A Guidebook for Nighttime Construction: Impacts on Safety, Quality, and Productivity Figure 8.7. Differences in nighttime and daytime temporary lane closures (Bryden 2004). Section 6A.01 General Support: 09 Operational improvements might be realized by using intelligent transportation systems (ITS) in work zones. The use in work zones of ITS technology, such as portable camera systems, highway advisory radio, variable speed limits, ramp metering, traveler information, merge guidance, and queue detection information, is aimed at increasing safety for both workers and road users and helping to ensure a more efficient traffic flow. The use in work zones of ITS technologies has been found to be effective in providing traffic monitoring and management, data collection, and traveler information. Figure 8.8. MUTCD language on ITS (FHWA 2009). Full body garments are recommended so that whole body movement is detectable by driv- ers. A properly-trained flagger, adjacent to a speed limit sign, can reduce average speeds by 5 to 10 mph (Bryden and Mace 2002b). Tip Arrange detours and work areas so flaggers are not needed.

Safety 87 Tip Flagging should not normally be considered a speed reduction technique for nighttime con- struction because flaggers are less visible and the risk to their safety is greater at night (Bryden and Mace 2002b). Tip Consider asking contractors for safety plans, especially if nighttime construction will be used. Tip Consider requiring safety history for contractor prequalification. Conclusions Nighttime construction activities present all the usual construction hazards risks. However, because of decreased visibility, additional safety hazards arise. Therefore, it is extremely impor- tant for agencies to take a focused approach to nighttime construction work-zone safety. The issue of visibility must receive constant attention, with contractors required to submit lighting plans and inspectors regularly checking work-site lighting. Necessary safety measures, such as proper safety plans and safety management, need to be implemented. This includes employer-provided safety training and awareness programs. All workers, including STA personnel, should undergo safety training and possess knowledge on safety precautions when performing nighttime work. In addition, effective and reliable work- zone traffic management should be designed and implemented. Night work can be safe for workers and work-zone–transiting vehicles. The key to a safe night- time project is planning, supported by the following: • Good temporary lighting. • Effective signs—brighter signs, larger signs, more signs. • Effective channelization—device spacing, retroreflectivity, warning lights. • Visible workers. • Visible work vehicles/equipment.