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Project Details
STATUS

Completed

START DATE

08/09/02

END DATE

08/09/02

RESEARCH CENTERS InTrans, SWZDI
SPONSORS

Wisconsin

Researchers
Principal Investigator
Alan J. Horowitz

University of Wisconsin, Milwaukee

Co-Principal Investigator
Thomas Notbohm

Wisconsin DOT

About the research

The Rumbler is a temporary rumble strip consisting of several plastic bumps that are six inches wide, four (to six) feet long, and between 0.15 and 0.25 inches high. They are affixed to the pavement with an adhesive. The Rumbler was installed on the northbound approach of a recently signalized intersection in rural Dodge County, WI. Vehicular speeds were measured both before and after the installation of the Rumbler to test the hypothesis that the warning would evoke an immediate driver response. In addition, noise and vibration levels interior to an automobile were recorded for both the Rumbler and a nearby conventional rumble strip. The Rumbler is much quieter than a conventional rumble strip. The Rumbler also produced considerably less vibrations in the test automobile. The quality of sound from the Rumbler is also distinctly different from a conventional rumble strip. However the Rumbler’s sound is qualitatively different and louder than road noise. The Rumbler did not elicit a large behavioral response from drivers. However, the Rumbler may have had the effect of reminding drivers of the need to be alert to the signal.

Project Details
STATUS

Completed

START DATE

08/11/12

END DATE

08/11/12

RESEARCH CENTERS InTrans, SWZDI
SPONSORS

Wisconsin

Researchers
Principal Investigator
Yue Liu

University of Wisconsin, Milwaukee

Co-Principal Investigator
Alan J. Horowitz

University of Wisconsin, Milwaukee

About the research

The effectiveness of work zone operational or control strategies is conditioned on a good estimate of the traffic volume though the work zone and amount of traffic diverting to alternate routes, as well as their resulting traffic impacts. Unfortunately, the ability to reliably estimate traffic diverting from work zones has not been adequately addressed, either in the professional literature or in practice. This project conducts an empirical study of traffic diversion at freeway work zones based on the analysis of collected field data. In addition, this study provides an understanding of how drivers behave when they encounter a work zone ahead. Data from traffic detectors, Bluetooth technology and a driver survey are collected at two rural work zones near Portage, WI and Tomah, WI. The findings from this study are further used to define traffic diversion estimation model. Such a model could enable a reliable estimation of diversion traffic at a target work zone. The model can be readily implemented in travel forecasting software.

Project Details
STATUS

Completed

START DATE

02/16/15

END DATE

02/16/15

RESEARCH CENTERS InTrans, SWZDI
SPONSORS

Wisconsin

Researchers
Principal Investigator
Yue Liu

University of Wisconsin, Milwaukee

Co-Principal Investigator
Yi Hu

University of Wisconsin, Milwaukee

Student Researcher(s)
Xin Li

About the research

This project develops a smartphone-based prototype system that supplements the 511 system to improve its dynamic traffic routing service to state highway users under non-recurrent congestion. This system will save considerable time to provide crucial traffic information and en-route assistance to travelers for them to avoid being trapped in traffic congestion due to accidents, work zones, hazards, or special events. It also creates a feedback loop between travelers and responsible agencies that enable the state to effectively collect, fuse, and analyze crowd-sourced data for next-gen transportation planning and management. This project can result in substantial economic savings (e.g. less traffic congestion, reduced fuel wastage and emissions) and safety benefits for the freight industry and society due to better dissemination of real-time traffic information by highway users. Such benefits will increase significantly in future with the expected increase in freight traffic on the network. The proposed system also has the flexibility to be integrated with various transportation management modules to assist state agencies to improve transportation services and daily operations.

Project Details
STATUS

Completed

START DATE

03/15/03

END DATE

03/15/03

RESEARCH CENTERS InTrans, SWZDI
SPONSORS

Wisconsin

Researchers
Principal Investigator
Alan J. Horowitz

University of Wisconsin, Milwaukee

Co-Principal Investigator
Thomas Notbohm

Wisconsin DOT

About the research

Intellizone is a product for giving advanced warning to drivers of slowing traffic entering work zones. Intellizone consists of a series of microwave detectors and portable message signs, linked together by wireless communication. The study site was the northbound direction of US 41 in Green Bay, Wisconsin, which underwent lane closures. There were two sources of data for evaluating the effectiveness of Intellizone: the Intellizone detectors and a questionnaire administered to drivers who had just passed through the work zone. Drivers were generally satisfied with the speed advisory signs and most drivers felt that the signs were accurate.

Vendor: Quixote/Hoosier

Project Details
STATUS

Completed

START DATE

07/05/05

END DATE

07/05/05

RESEARCH CENTERS InTrans, SWZDI
SPONSORS

Wisconsin

Researchers
Principal Investigator
Alan J. Horowitz

University of Wisconsin, Milwaukee

Co-Principal Investigator
Thomas Notbohm

Wisconsin DOT

About the research

The purpose of this project was to help identify the optimal design of temporary rumble strips that would be used in a work zone. The project involved a focus group and a psychological scaling experiment, where each subject was asked to evaluate a temporary rumble strip relative to a cut-in-pavement rumble strip. In addition, sound and vibration measurements were made from within a vehicle passing over the strips. The ATM rumble strips (0.25 inches thick) were deployed within an actual work zone in Washington County (WI), while the RTI strips (0.75 inches thick) were tested in a large parking lot. An ATM strip when traversed at 55 mph was about as effective a warning device as a cut-in-pavement rumble strip. This same strip configuration when traversed at 40 mph was ineffective. The RTI product is an effective warning device for vehicle speeds between 10 and 40 mph.

Vendors: Advanced Traffic Markings and RTI

Project Details
STATUS

Completed

START DATE

08/11/09

END DATE

08/11/09

RESEARCH CENTERS InTrans, SWZDI
SPONSORS

Wisconsin

Researchers
Principal Investigator
Alan J. Horowitz

University of Wisconsin, Milwaukee

About the research

This research applied microscopic traffic simulation to freeway work zones to further understand the relationship between traffic variables and capacity. There are two distinct forms of capacity depending upon the flow regime: capacity while traffic is free flowing and capacity while traffic is queued. Actual work zones from the Milwaukee freeway systems were varied by simulation to obtain relationships between capacity and truck volume, lane distribution, ramp location, ramp volumes, grade and merging schemes. Capacity was found to be a random variable, even when all prevailing conditions are held constant, because of stochastic variations in vehicle mix, lane distribution and driver behavior. Capacity was found to be significantly affected by prevailing conditions of grade, vehicle mix, and the lane distribution of trucks.

Project Details
STATUS

Completed

START DATE

08/07/09

END DATE

08/07/09

RESEARCH CENTERS InTrans, SWZDI
SPONSORS

Wisconsin

Researchers
Principal Investigator
Alex Drakopoulos

Marquette University

Co-Principal Investigator
Thomas Notbohm

Wisconsin DOT

Co-Principal Investigator
Amjad Dehman

Marquette University

About the research

The focus of this report is a capacity analysis of two long-term urban freeway Work Zones. Work Zone 1 tapered four mainline lanes to two, using two separate tapers; Work Zone 2 tapered two mainline lanes to one. Work Zone throughput was analyzed throughout the day over multiple days and traffic operations conditions were analyzed up to a distance of five miles upstream of the Work Zone entrance. Historical data from pavement-embedded detectors were used to analyze traffic conditions. The database consisted of five-minute volume, speed and occupancy data collected from 78 detectors for a total of 50 days.

Congestion during each analyzed Work Zone existed for more than fourteen hours each day; Work Zone impacts adversely affected freeway operations over distances of 3.7 to 4.2 miles. Speed and occupancy conditions further upstream were, however, not affected, or even improved due to significant trip diversion. Work Zone capacity was defined based on the maximum traffic flows observed over a one-hour period; throughput values were also compiled over longer periods of time when traffic was within 90% of the maximum observed one-hour flows, as well as over the multi-hour mid-day period. The Highway Capacity Manual freeway capacity definition based on the maximum observed 15-min period was not used, since it would have no practical application in estimating Work Zone throughput when congested conditions prevail for the majority of the hours of the day.

Certain noteworthy changes took place for the duration of the analyzed Work Zones: per-lane throughput dropped; morning peak periods started earlier, evening peak periods ended later and lasted longer; mid-day volumes dropped accompanied by the highest occupancies of the day. Trip diversion was evident in lower volumes entering the analyzed freeway corridor, higher volumes using off-ramps and lower volumes using on-ramps upstream of the Work Zones. The majority of diverted traffic comprised smaller vehicles (vehicles up to 21 feet in length); combination truck volumes increased and their use of the median lane increased, contrary to smaller vehicles that shifted toward a heavier use of the shoulder lane.

Project Details
STATUS

Completed

START DATE

08/08/17

END DATE

08/08/17

RESEARCH CENTERS InTrans, SWZDI
SPONSORS

Wisconsin

Researchers
Principal Investigator
Madhav Chitturi

University of Wisconsin, Madison

Principal Investigator
Praveen Edara

University of Missouri-Columbia

Co-Principal Investigator
John Shaw

Researcher, CTRE

Co-Principal Investigator
Carlos Sun
Co-Principal Investigator
Henry Brown

University of Missouri - Columbia

Student Researcher(s)
Zhu Qing

About the research

Many work zones require lane closures, and road users need to be notified of these closures through appropriate upstream signage. A literature review prepared for this study found several previous investigations indicating insufficient comprehension of the U.S. standard lane closure sign (designated in the Manual on Uniform Traffic Control Devices for Streets and Highways [MUTCD] as W4-2) and similar signs used internationally. The W4-2 sign is also unsuitable for signing interior lane closures on roadways with three or more lanes. Driver comprehension of several alternative sign faces was tested through a survey using the ANSI Z535.3 process and was followed by a driving simulator study. The driver comprehension survey suggests that an Upward Drop Arrow design is a promising alternative to the existing W4-2 sign for sites where two upstream lanes are reduced to one lane in the work zone. In addition, one-arrow-per-lane signs developed as Americanized versions of the Vienna Convention G12a sign template are a promising option for interior lane closures on multi-lane roadway segments. A driving simulator study compared the W4-2, a MERGE text sign with a horizontal arrow, and an Americanized version of the Vienna Convention G12a sign. In terms of sign comprehension, the W4-2 was the least understood of the three signs. The W4-2 resulted in more late merge maneuvers than the other two signs. Field evaluation of the Upward Drop Arrow and Americanized G12a signs is recommended as a follow-up to this study.

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