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Project Details
STATUS

Completed

START DATE

08/11/08

END DATE

08/11/08

RESEARCH CENTERS InTrans, SWZDI
SPONSORS

Kansas

Researchers
Principal Investigator
Steven D. Schrock

University of Kansas

Co-Principal Investigator
Chen Fei See

University of Kansas

Co-Principal Investigator
Thomas E. Mulinazzi

University of Kansas

Co-Principal Investigator
Matthew T. Becker

University of Kansas

About the research

This research examined the safety and operational benefits of having traffic merge early into the open lane prior to a work zone merge area. A 2007 law in Oklahoma adopted the use of additional STATE LAW MERGE NOW static signing in the advance warning areas approximately 1/2-mile upstream from freeway merge areas. Work zones that were continuations from the 2006 construction season did not use this signing, while new work zones did. This provided a unique opportunity to compare the impact of early merge signing in actual work zone environments. Measures of effectiveness examined included the number and percentage of traffic that remained in the closed lane and the number of conflicts that occurred at the merge area.

It was found that the early merge signs did not appear to reduce the percentage of vehicles that remained in the closed lane. However, at least for right-lane closures, there appeared to be a significant benefit to using the STATE LAW MERGE NOW signing to reduce the number of observed conflicts at the merge area. This was evident when the hourly volumes were more than 550 vph. It seemed likely that although the early merge signs themselves did not improve early merging, the signs seemed to encourage drivers to consider earlier how they would make their merge maneuver, so when the reached the merge area the drivers that must merge were more likely to be able to make the merge without the need to vie for position against other drivers.

Project Details
STATUS

Completed

START DATE

08/11/08

END DATE

08/11/08

RESEARCH CENTERS InTrans, SWZDI
SPONSORS

Kansas

Researchers
Principal Investigator
Steven D. Schrock

University of Kansas

About the research

In long-term work zones on multilane highways and/or freeways, the Federal Highway Administration has interpreted the Manual on Uniform Traffic Control Devices to mean that only one advance warning arrow displays can be used to denote the closure of a single lane. Where two or more lanes are closed, a single arrow display is used for each lane to be closed. However, in short duration, mobile, and moving work convoys the MUTCD allows the use of multiple arrow displays to indicate a single lane closure. These disparate uses for arrow displays create the potential for confusion by drivers.

This paper describes the results of four focus group interviews with Midwestern drivers. Participants were shown several mocked images of shadow work vehicles with arrow displays and were questioned on how well they understood and/or interpreted the message conveyed by arrow displays depending on the display type and quantity of displays used, and looked specifically for potential driver confusion.

Focus group participants generally considered panel displays that included motion (e.g., sequential arrows and sequential chevrons) as implying a more important situation and preferred their use over flashing versions. While participants were receptive to the use of multiple arrow displays on multiple shadow vehicles, a minority indicated that this conveyed a need to move over more than one lane. Participants also indicated that staggering sequential shadow vehicles from the shoulder into the closed lane provided useful information as to the number and location of the closed lanes.

Project Details
STATUS

Completed

START DATE

08/11/09

END DATE

08/11/09

RESEARCH CENTERS InTrans, SWZDI
SPONSORS

Kansas

Researchers
Principal Investigator
Steven D. Schrock

University of Kansas

Co-Principal Investigator
Chen Fei See

University of Kansas

Co-Principal Investigator
Thomas E. Mulinazzi

University of Kansas

About the research

Communications between high-technology devices in work zones has long been a challenge. The problem is acute in rural areas where there is often little or no existing infrastructure to support wireless communication to the same extent as in urbanized areas. Despite this, there is often a desire to use real-time communications between new technologies to provide accurate work zone information to motorists or to remotely monitor work zone operations. An opportunity exists with new decentralized wireless communications technology known as mesh networks. Typically available in the license-free spectrums, a mesh network is by definition rapidly deployable and automatically configured, precisely what is needed to blanket a rural work zone.

The findings of this proof-of-concept study showed that mesh networking would be great fit to blanket the work zones in rural areas. The system used in this research was capable of providing enough bandwidth to allow over 500 kbps of continuous data at over 3500 m (2.17 mi), more than would be required for an online video conference (384 kbps) and also more than would be required for voice communications (120 kbps). This level of data transmission would far exceed that required to transmit GPS position data that would be required to update a CMS with an estimated time of arrival for queued vehicles waiting at a work zone.

Project Details
STATUS

Completed

START DATE

08/11/02

END DATE

08/11/02

RESEARCH CENTERS InTrans, SWZDI
SPONSORS

Kansas

Researchers
Principal Investigator
Eric Meyer

University of Kansas

Co-Principal Investigator
Scott Walton

University of Kansas

About the research

A previous evaluation of this product found that the ease of application and removal represented a significant advantage over traditional asphalt rumble strips, but that a single thickness was insufficient to be reliably perceptible by drivers. The orange color of the strips was found to cause a reduction in mean speed, even though little or no sound or vibration was generated. This evaluation was conducted as a followup to explore four issues: 1) the effectiveness of the strips installed in a double thickness, 2) the persistence of the speed reduction due to the orange color (i.e., is this a novelty effect), 3) the quantified sound and vibration generated inside the vehicle compared to asphalt strips, and 4) the durability of the strips as installed per manufacturer’s specifications. A rural two-lane highway was identified where bridge repairs were to require a lane closure and installation of a temporary signal. KDOT standards require two sets of rumble strips on each approach whenever a temporary signal is used. Traditional asphalt strips were used on one approach to the site, while on the other approach the removable strips were used for the most upstream set of strips. Vehicle speeds were monitored on both approaches for several weeks, installation and removal time was measured, and sound and vibration inside the vehicle were measured for both the orange rumble strips and the asphalt rumble strips. The double thickness of this strip was found to be effective, generating similar sound and vibration to the asphalt strips. They are more expensive than asphalt strips, and reuse is not recommended by the manufacturer. The shorter installation times to imply safety benefits, although these were not quantified. The orange color of the strips was responsible for a reduction in mean speeds, but the reduction dissipated over time.

Vendor: Advanced Traffic Markings

Project Details
STATUS

Completed

START DATE

08/11/00

END DATE

08/11/00

RESEARCH CENTERS InTrans, SWZDI
SPONSORS

Kansas

Researchers
Principal Investigator
Eric Meyer

University of Kansas

About the research

The devices were easily deployed and appear to provide more positive guidance that standard reflectorized drums. Lane distributions were monitored upstream of the taper, and no significant difference was observed between the time period when the SafetyCade units were used and when the taper was delineated by barrels alone, supporting the device as being as effective as drums. When used in areas noted for wind or where highway speeds are prevalent, the weighted boot should be used.

Vendor: WLI Industries

Project Details
STATUS

Completed

START DATE

08/11/00

END DATE

08/11/00

FOCUS AREAS

Safety

RESEARCH CENTERS InTrans, SWZDI
SPONSORS

Kansas

Researchers
Principal Investigator
Eric Meyer

University of Kansas

About the research

The RPMs were easily installed and relatively low maintenance. The data showed no observable change in lane distributions that could be attributed to the greater visibility of the taper after installation of the RPMs. Subjective evaluation and review of driver’s view video footage suggested that the light emitted from the units was not sufficient to effectively improve taper delineation.

Vendor: Interplex Solar

Project Details
STATUS

Completed

START DATE

08/11/00

END DATE

08/11/00

RESEARCH CENTERS InTrans, SWZDI
SPONSORS

Kansas

Researchers
Principal Investigator
Eric Meyer

University of Kansas

About the research

This project designed and evaluated a system of lighted RPMs used to delineate a crossover in advance of an Interstate work zone. Vehicle speeds were collected at the crossover and approximately half a mile upstream of the crossover. Lane keeping data was also collected by utilizing several automatic traffic recorders, a complex array of pneumatic hoses, and some custom software. The system was found to result in statistically significant reductions in speed and in the number of vehicles nearing the edgeline (i.e., within 1-ft for cars, 2-ft for trucks). The system demonstrated the capability to improve delineation in a rural rossover, but the need for power to operate the lights could be problematic in some locations. Because the system was experimental, no cost figures are available.

Vendor: LightGuard Systems, Inc.

Project Details
STATUS

Completed

START DATE

08/11/00

END DATE

08/11/00

RESEARCH CENTERS InTrans, SWZDI
SPONSORS

Kansas

Researchers
Principal Investigator
Eric Meyer

University of Kansas

About the research

Two drone radar units were deployed at a rural Interstate work zone where traffic was limited to one lane in each direction for a reconstruction project. Speed data were collected at several locations over about a 1-mi segment for a week prior to deployment and a week following deployment. Some speed differences observed between the before and after data were statistically significant, but the differences were inconsistent. In some locations the speeds decreased after deployment, and in other locations they increased. No explanations for the changes could be identified, but their inconsistency suggests that the radar drone is not an effective speed control device.

Vendor: Speed Measurement Labs

Project Details
STATUS

Completed

START DATE

08/11/00

END DATE

08/11/00

RESEARCH CENTERS InTrans, SWZDI
SPONSORS

Kansas

Researchers
Principal Investigator
Eric Meyer

University of Kansas

About the research

A radar actuated speed display board was deployed in a rural Interstate work zone in which traffic was reduced to one lane in each direction. Speeds were measured at several locations over a span of about a mile. Data were collected without the display for one week and then with the display in operation for another week. Comparison of traffic characteristics showed statistically significant decreases in mean speed, 85th percentile speed, and percent speeding, both at the display location and as much as half a mile downstream. The mean speed reduction between the before (without the display) and after (with the display) data was about 3 mph at the display and about 1 mph half a mile downstream. Data were also collected for several hours while a Kansas Highway Patrol (KHP) vehicle was positioned at the same location. Changes in speed characteristics relative to baseline conditions were similar to those observed with the speed display at the display/vehicle location. A half-mile downstream, though, speeds were well above baseline speeds when the KHP was present.

Vendor: Speed Measurement Labs

Project Details
STATUS

Completed

START DATE

08/11/01

END DATE

08/11/01

RESEARCH CENTERS InTrans, SWZDI
SPONSORS

Kansas

Researchers
Principal Investigator
Eric Meyer

University of Kansas

About the research

This evaluation featured a trailer mounted highway advisory radio transmitter. The mobile maintenance operation during which this device was to be tested was performed in such a way that the device was no longer useful for its intended purpose. Data collection was cancelled. Maintenance procedures related to striping operations in Kansas are not conducive to effective use of HAR.

Addendum: Since the completion of this evaluation and the associated report, the Kansas DOT has purchased several mobile HAR units for use at the State Fair, at NASCAR events at the Kansas Speedway, and at other events as needed. Anecdotal reports of the effectiveness of the devices are very favorable and continued use is planned.

Vendor: Highway Info Systems

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