Sustained and Halo Effects of Various Speed Reduction Treatments in Highway Work Zones

2011 ◽  
Vol 2265 (1) ◽  
pp. 118-128 ◽  
Author(s):  
Ali Hajbabaie ◽  
Juan C. Medina ◽  
Ming-Heng Wang ◽  
Rahim (Ray) F. Benekohal ◽  
Madhav Chitturi
Keyword(s):  
Work Zones ◽  
Speed Reduction ◽  
Halo Effects

Effect of Lane Width on Speeds of Cars and Heavy Vehicles in Work Zones

2005 ◽  
Vol 1920 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Madhav V. Chitturi ◽  
Rahim F. Benekohal
Keyword(s):  
Flow Speed ◽  
Heavy Vehicles ◽  
Work Zones ◽  
Passenger Cars ◽  
Highway Capacity ◽  
Speed Reduction ◽  
Interstate Highways ◽  
Highway Capacity Manual ◽  
Traffic Stream ◽  
Lane Width

Traffic data were collected from 11 work zones on Interstate highways in Illinois in which one of the two lanes was open. The reductions in free-flow speed (FFS) due to narrow lanes and lateral clearances in work zones were studied. It was found that the reductions in FFSs of vehicles in work zones because of narrow lanes were higher than the reductions given in the Highway Capacity Manual for basic freeway sections. The data also showed that the narrower the lane was, the greater the speed reduction was. The data showed that the FFSs of heavy vehicles were statistically lower than the FFSs of passenger cars, even though the speed limit was the same for both types of vehicles. In addition, the reduction in the FFSs of heavy vehicles was greater than the reduction in the FFSs of passenger cars. This greater reduction in the speed of heavy vehicles affected the performance of the traffic stream in work zones. Thus, it should be considered in the computation of the passenger car equivalence for heavy vehicles. It is recommended that 10, 7, 4.4, and 2.1 mph be used for speed reduction in work zones for lane widths of 10, 10.5, 11, and 11.5 ft, respectively.

Evaluating Speed-Reduction Strategies for Highway Work Zones

2003 ◽  
Vol 1824 (1) ◽  
pp. 44-53 ◽  
Author(s):  
Chunyan Wang ◽  
Karen K. Dixon ◽  
David Jared
Keyword(s):  
Traffic Control ◽  
Statistical Tests ◽  
Work Zones ◽  
Control Zone ◽  
Novelty Effect ◽  
Speed Reduction ◽  
Reduction Strategies ◽  
Changeable Message Signs ◽  
Message Signs ◽  
Over Time

Research was conducted to identify the potential of fluorescent orange sheeting, innovative message signs, and changeable message signs with radar for reducing speeds in highway work zones. The study investigated the effect of each strategy immediately after implementation (immediate effect) as well as several weeks after implementation (novelty effect). In addition to the overall effect of each strategy on all vehicles, the study included the effect on specific vehicle types during various lighting conditions. The researchers collected traffic data before, immediately after, and 2 or 3 weeks after implementation of each strategy (3 consecutive weeks for the changeable message sign). They collected data upstream of the temporary traffic-control zone, in the advancewarning area, and adjacent to the active work area. The researchers used various statistical tests to evaluate the significance of speed changes from phase to phase and adjusted vehicle speeds with the upstream speed changes over time. The study indicated that fluorescent orange sheeting and innovative message signs help reduce speeds at highway work zones (with diminished influence over time). Moreover, both strategies influence vehicle speeds more during the day than at night. Drivers of passenger vehicles tended to decrease their speeds more than did truck drivers. Changeable message signs with radar significantly reduced the vehicle speeds in the immediate vicinity of the sign and did not demonstrate a novelty effect.

Downstream Effects of Speed Photo–Radar Enforcement and Other Speed Reduction Treatments on Work Zones

2009 ◽  
Vol 2107 (1) ◽  
pp. 24-33 ◽  
Author(s):  
Juan C. Medina ◽  
Rahim F. Benekohal ◽  
Ali Hajbabaie ◽  
Ming-Heng Wang ◽  
Madhav V. Chitturi
Keyword(s):  
Work Zones ◽  
Speed Reduction ◽  
Downstream Effects ◽  
Photo Radar

Spacing of Law Enforcement Pullout Areas in Highway Work Zones

2003 ◽  
Vol 1824 (1) ◽  
pp. 37-43
Author(s):  
Steven D. Schrock ◽  
Gerald Ullman
Keyword(s):  
Law Enforcement ◽  
Delphi Method ◽  
Law Enforcement Officers ◽  
Work Zone ◽  
Work Zones ◽  
Traffic Enforcement ◽  
Relative Difficulty ◽  
Speed Reduction ◽  
Reduction Methods ◽  
Effective Speed

Law enforcement presence in work zones has long been recognized as one of the most effective speed-reduction methods available to transportation officials. Unfortunately, the design of many work zones makes effective enforcement difficult. Work zones that have no emergency shoulders on either side of the roadway are especially problematic. Incorporating enforcement pullout areas into construction phasing plans has been suggested as a way to improve enforcement activities. However, no guidance had been available on how frequently such enforcement areas should be incorporated. Research was conducted to determine law enforcement and contractor opinions on acceptable spacing criteria for pullout areas in a highway work zone. Two sets of surveys were made by using the Delphi method to solicit the opinions of law enforcement officers and roadway contractors regarding the relative difficulty or effectiveness of pullout areas located at various spacings through a long work zone. The Delphi method was used to quickly bring these groups to consensus. Construction contractors generally were against placing pullout areas closer than 2 mi apart. By contrast, law enforcement officers indicated that at spacing greater than 3 mi, the pullout area would not be useful for traffic enforcement. The results indicate that enforcement pullout areas in work zones should be spaced approximately every 2 to 3 mi or, as an alternative, work zones that eliminate emergency shoulders that are adequate for enforcement purposes should be no longer than 3 mi.

The Effect of In-Vehicle Warning Systems on Speed Compliance in Work Zones

2010 ◽  
Author(s):  
James Whitmire ◽  
J. F. Morgan ◽  
Tal Oron-Gilad ◽  
P. A. Hancock
Keyword(s):  
Warning Systems ◽  
Work Zones

Quantification of the impact of traffic incidents on speed reduction: A causal inference based approach

2021 ◽  
Vol 157 ◽  
pp. 106163
Author(s):  
Danni Cao ◽  
Jianjun Wu ◽  
Xianlei Dong ◽  
Huijun Sun ◽  
Xiaobo Qu ◽  
...  
Keyword(s):  
Causal Inference ◽  
Traffic Incidents ◽  
Speed Reduction ◽  
The Impact
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