Work Zone Speed Management (2015)

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80 chapter ten SURVEY OF WORK ZONE ENGINEERING AND ENFORCEMENT PRACTICES INTRODUCTION Two online surveys were conducted to gain an understand- ing of the current state of practice regarding work zone speed management by highway agencies. This chapter summarizes the findings of the Engineering and Enforcement survey. An invitation to participate in the survey was distributed to members of the AASHTO Standing Committee on Traffic Engi- neering. The invitation list was further augmented by inviting members of the FHWA Work Zone Safety Peer Exchange and work zone engineering professionals from Canadian provin- cial MOTs. In all, 50 responses were received, including four Canadian MOTs. In addition, four DOTs in the United States provided more than one response, typically one response from the agency’s headquarters and a response from a regional or district office. The U.S. respondents are shown in Figure 55 and the survey instrument is attached as Appendix A. KEY FINDINGS As indicated in Table 3 (located in chapter two), approxi- mately two-thirds of the agencies that responded to the survey reported that they have a written speed limit setting procedure or policy in place. Just over half of the respondents indicated that the policy is uniformly implemented; however, 40% did not respond to this question. Agencies were asked about several signing and marking techniques that have the potential to reduce traffic speeds in work zones. The results are tabulated in Tables 14 and 15 and can be summarized as follows: • Dynamic work zone speed limit signage is rarely used; however, when it is applied, it is used primarily for free- way projects that involve unusual situations. • About half of all respondents indicated the use of man- datory reduced speed limits when workers are present. According to the survey responses, the signs were more commonly used on two-lane rural highway projects than on freeways. • On freeway projects, the vast majority of responding agencies frequently use fines doubled in work zones signs or analogous signage indicating the higher penalties authorized under their respective laws. In some jurisdic- tions this type of signage is mandatory or must be in place for the higher fines to be enforceable. Most respondents noted that such signs were used only in special situations on two-lane rural highway projects. • By and large the use of dynamic speed feedback signs appears to be limited to special situations. • Currently, there is limited use of transverse rumble strips at work zones. Although the survey responses indicated occasional use for freeway work zones, interviews with DOT personnel suggest that the primary use is to encour- age drivers to decelerate in advance of flagger stations at two-way, one-lane work zones. • Currently, the use of optical bar markings at work zones is uncommon. • Agencies occasionally use narrowed lanes as a speed management measure. The use of modified cone or barrel spacing to encourage speed reduction is more common. • The use of pace cars and pilot vehicles is fairly common, with 44% of respondents indicating their use on freeway projects (presumably for rolling closures) and 76% of respondents indicating their use on two-lane, rural high- way projects (presumably as pilot vehicles in work zones that are long, traverse rugged terrain, or involve bringing live traffic very close to workers). • Advance warning signs indicating a speed reduction ahead are widely used on freeway projects, but seldom used on two-lane, rural highway projects. • Wide edgelines are rarely used as a work zone speed management measure. The survey responses regarding enforcement techniques are detailed in Tables 16 and 17 and can be summarized as follows: • Standard active enforcement remains the most common tactic for work zones. • About one-third of the respondents reported frequent use of police officers in work zones who have their flashing lights on to indicate presence, but do not issue tickets. About one-quarter of the respondents use the same tactic, but with lights off. • Decoy police vehicles and aerial enforcement are seldom used in work zones. • Stealth enforcement, such as radar spotters on an over- pass, is used by about one-quarter of the agencies in special situations. • Automated issuance of warnings (not citations) is rare. • By and large decoy radar is used only in special situations. As shown in Figure 56, most agencies tolerate speeding to some degree. The most frequently reported tolerance range was 4 to 6 mph, and the second most frequently reported range was 9 to 10 mph.

81 FIGURE 55 U.S. respondents to engineering and enforcement survey. Engineering Techniques for Freeway Work Zones All Work Zones Most Work Zones Some Work Zones Occasional/ Unique Situations Never No Response Total Dynamic Work Zone Speed Limit Signs 2% 0% 8% 32% 58% 0% 100% Mandatory Reduced Speed Limit only When Workers Present 18% 14% 14% 8% 44% 2% 100% “Fines Doubled in Work Zones” Signage 50% 28% 16% 0% 4% 2% 100% Dynamic Speed Feedback Signs 2% 4% 18% 56% 18% 2% 100% Transverse Rumble Strips at Approach to Work Zone 0% 0% 8% 50% 42% 0% 100% Converging Bar Pavement Markings (optical speed bars) 0% 0% 0% 10% 90% 0% 100% Reduction of Lane Width to Encourage Slower Driving 0% 2% 14% 36% 44% 4% 100% Modified Cone/Barrel Spacing to Encourage Slower Driving 0% 6% 20% 22% 52% 0% 100% Pace Cars/Pilot Vehicles 0% 2% 42% 24% 32% 0% 100% Speed Reduction Warning Signs 14% 40% 34% 8% 4% 0% 100% Wide (10 in.) Edgelines 2% 0% 4% 18% 74% 2% 100% TABLE 14 ENGINEERING MEASURES USED BY SURVEY RESPONDENTS ON FREEWAY AND OTHER MULTILANE DIVIDED HIGHWAY WORK ZONES IN THE PREVIOUS THREE YEARS

82 Engineering Techniques for Two-Lane Highway Work Zones All Work Zones Most Work Zones Some Work Zones Occasional/ Unique Situations Never No Response Total Dynamic Work Zone Speed Limit Signs 0% 0% 6% 22% 70% 2% 100% Mandatory Reduced Speed Limit only When Workers Present 48% 18% 20% 4% 6% 4% 100% “Fines Doubled in Work Zones” Signage 0% 2% 12% 60% 24% 2% 100% Dynamic Speed Feedback Signs 0% 2% 18% 38% 40% 2% 100% Transverse Rumble Strips at Approach to Work Zone 0% 0% 0% 6% 92% 2% 100% Converging Bar Pavement Markings (optical speed bars) 0% 0% 12% 44% 42% 2% 100% Reduction of Lane Width to Encourage Slower Driving 0% 6% 12% 32% 48% 2% 100% Modified Cone/Barrel Spacing to Encourage Slower Driving 0% 2% 56% 24% 16% 2% 100% Pace Cars/Pilot Vehicles 10% 32% 34% 14% 8% 2% 100% Speed Reduction Warning Signs 0% 0% 4% 10% 84% 2% 100% Wide (10 in.) Edgelines 16% 8% 16% 6% 52% 2% 100% TABLE 15 ENGINEERING MEASURES USED BY SURVEY RESPONDENTS ON HIGH-SPEED, TWO-LANE, HIGHWAY WORK ZONES IN THE PREVIOUS THREE YEARS Freeway Work Zone Enforcement Techniques All Work Zones Most Work Zones Some Work Zones Occasional/Unique Situations Never No Response Count Police Vehicles in Work Zone— Active Enforcement 2% 16% 52% 26% 0% 4% 100% Police Vehicles (flashing lights OFF) Present in Work Zone, but Not Issuing Tickets 0% 2% 22% 28% 44% 4% 100% Police Vehicles (flashing lights ON) Present in Work Zone, but Not Issuing Tickets 2% 12% 24% 24% 34% 4% 100% Decoy Police Vehicles 0% 0% 0% 18% 78% 4% 100% Aerial Enforcement 0% 0% 4% 16% 76% 4% 100% Enhanced/Stealth Enforcement (spotters on overpass or shoulder) 0% 0% 8% 24% 64% 4% 100% Automated Enforcement/Speed Cameras 0% 0% 6% 6% 84% 4% 100% Decoy Speed Cameras 0% 0% 0% 2% 94% 4% 100% Automated Issuance of Written Warnings (non-citation) 0% 0% 2% 4% 90% 4% 100% Decoy Radar 0% 0% 4% 10% 82% 4% 100% TABLE 16 ENFORCEMENT MEASURES USED BY SURVEY RESPONDENTS ON FREEWAY AND OTHER MULTILANE DIVIDED HIGHWAY WORK ZONES IN THE PREVIOUS THREE YEARS

83 Two-Lane Rural Highway Work Zone Enforcement Techniques All Work Zones Most Work Zones Some Work Zones Occasional/Unique Situations Never No Response Count Police Vehicles in Work Zone— Active Enforcement 0% 10% 40% 32% 14% 4% 100% Police Vehicles (flashing lights OFF) Present in Work Zone, but Not Issuing Tickets 0% 2% 18% 24% 52% 4% 100% Police Vehicles (flashing lights ON) Present in Work Zone, but Not Issuing Tickets 0% 4% 22% 16% 54% 4% 100% Decoy Police Vehicles 0% 0% 0% 12% 84% 4% 100% Aerial Enforcement 0% 0% 4% 10% 80% 6% 100% Enhanced/Stealth Enforcement (spotters on overpass or shoulder) 0% 0% 0% 20% 76% 4% 100% Automated Enforcement/Speed Cameras 0% 0% 2% 4% 90% 4% 100% Decoy Speed Cameras 0% 0% 0% 2% 94% 4% 100% Automated Issuance of Written Warnings (non-citation) 0% 0% 2% 0% 94% 4% 100% Decoy Radar 0% 0% 4% 2% 90% 4% 100% TABLE 17 ENFORCEMENT MEASURES USED BY SURVEY RESPONDENTS ON TWO-LANE RURAL HIGHWAY WORK ZONES IN THE PREVIOUS THREE YEARS FIGURE 56 Reported law enforcement speeding tolerance/ticketing thresholds. 2% 0% 0% 2% 4% 22% Enforcement Ticketing Threshold (MPH) Speed Enforcement Threshold (MPH) Pe rc en ta ge o f R es po nd en ts 8% 2% 4% 10% 22% 24% 0% 5% 10% 15% 20% 25% 30% 0 1 2 3 4 5 6 7 8 9 10 No Response