Institute for Transportation

About the research

Road maintenance activities involve both short-term stationary work zones and moving work zones. Moving work zones typically involve striping, sweeping, pothole filling, shoulder repairs, and other quick maintenance activities. Existing traffic analysis tools for work zone scheduling are not designed to model moving work zones.

A review of existing literature showed that many of the existing studies of moving bottlenecks are theoretical in nature, limited to certain lane configurations, and restrictive in the types of mobile work zone attributes considered. This research project sought to address this gap in existing knowledge by using field data from moving work zones to develop and calibrate a traffic impact analysis tool.

This objective was accomplished through the fusion of multiple sources of work zone and traffic data. Four different data sources were used: Missouri Department of Transportation (MoDOT) electronic alerts (e-alerts), probe-based travel times, data from point detectors, and field videos of moving work zones recorded from the back of a truck-mounted attenuator (TMA).

A linear regression model was developed to predict traffic speed inside a moving work zone. Predictor variables in the models included historical speed, number of lanes, type of lane closure, and time of day. The simulation tool VISSIM was calibrated for moving work zones using information extracted from videos of moving work zone operations. The three recommended calibration parameters are a safety reduction factor of 0.7, a minimum look ahead distance of 500 ft, and the use of a smooth closeup option. These calibration values can be used by departments of transportation (DOTs) to model moving work zone scenarios.

The operational analysis concluded that a moving work activity lasting one hour or more operates best when traffic volumes are under 1,400 veh/hr/ln, and preferably under 1,000 veh/hr/ln. Further, scheduling shorter duration moving activities on high-volume roads at multiple times (on the same day or on different days) works better than scheduling a longer duration activity. The safety analysis generated tradeoff plots between the number of conflicts and combinations of activity duration and traffic volume. A DOT can use these plots to determine, for example, if it should conduct a moving work activity for a short duration when the volume is high or for a longer duration when the volume is lower.

Funding Sources:
Midwest Transportation Center
Smart Work Zone Deployment Initiative ($50,000.00)
USDOT/OST-R ($50,185.00)
Total: $100,185.00

Contract Number: DTRT13-G-UTC37

About the research

This project investigated the factors impacting individual vehicle energy consumption, including vehicle characteristics, ambient temperature, season, speed, driving behavior, and traffic flow. A fleet of 18 vehicles with a variety of ownership, size, model, year, and powertrain characteristics was monitored using on-board diagnostics II (OBD-II) loggers to collect each vehicle’s controller area network (CAN) bus data for a one-year period.

Traffic data, including flow rate, space mean speed, and density, were also collected and linked with the vehicle data. Based on vehicle CAN bus data, fuel consumption models for gasoline vehicles were calibrated, and a new electricity consumption model for electric vehicles was proposed. Both models can reliably estimate individual vehicle energy consumption.

Funding Sources:
Iowa State University ($41,261.00)
Midwest Transportation Center
USDOT/OST-R ($40,000.00)
Total: $81,261.00

Contract Number: DTRT13-G-UTC37

About the research

The Federal Highway Administration (FHWA) has developed and promoted geosynthetic reinforced soil-integrated bridge system (GRS-IBS) technology to deliver accelerated bridge construction economically, primarily for relatively small bridges. The technology harnesses the stiffness of GRS to eliminate the need for piling or other conventional foundation systems. Eliminating piling typically results in cost and schedule benefits.

Despite the cost and time savings and performance benefits associated with GRS-IBS technology, it has not experienced widespread implementation. Use of the technology is likely becoming more common and widespread, particularly with several agencies deploying GRS-IBS on numerous occasions. However, other agencies have likely not implemented GRS-IBS because of a lack of familiarity with the technology and its implementation benefits.

To help overcome this lack of familiarity, the research team documented recent implementations focusing on technical performance and practical lessons from agency experiences in contracting and constructing these types of bridges. These GRS-IBS experiences were culled from a literature review, interviews with agency and contractor personnel, and the research team’s experience with construction and performance observations of the Rustic Road GRS-IBS project in Boone County, Missouri.

The final report, tech transfer summary, and implementation aid that were developed as a result of this work are for two Midwest Transportation Center research projects: Advancing Implementation of Geosynthetic Reinforced Soil-Integrated Bridge Systems (GRS-IBS) and Implementation Evaluation of the Rustic Road Geosynthetic Reinforced Soil-Integrated Bridge System.

Funding Sources:
Midwest Transportation Center
University of Missouri – Columbia ($44,999.00)
USDOT/OST-R ($71,349.00)
Total: $116,348.00

Contract Number: DTRT13-G-UTC37

About the research

The objective of this research is to develop guidelines to improve the quality of element-level data collection for bridges on the National Highway System (NHS) in reference to the AASHTO Manual for Bridge Element Inspection.

Funding Sources:
Midwest Transportation Center
National Cooperative Highway Research Program (NCHRP) ($120,000.00)
USDOT/OST-R ($120,000.00)
Total: $240,000.00

Contract Number: DTRT13-G-UTC37

About the research

The objective of this project is to develop new nondestructive evaluation (NDE) technology for the condition assessment of post-tensioned bridge components.

Funding Sources:
Midwest Transportation Center
Missouri Department of Transportation ($50,593.00)
University of Missouri – Columbia ($9,407.00)
USDOT/OST-R ($60,000.00)
Total: $120,000.00

Contract Number: DTRT13-G-UTC37

About the research

In this project, a bridge maintenance and preservation program was developed for the City of Columbia, Missouri. The program focuses on practical and implementable technologies and procedures that can be applied to extend the service lives of the bridges, reduce maintenance costs, and ensure safety and serviceability. Specific technologies that were considered included bridge deck flushing, fog and seal programs, and crack sealers.

The researchers analyzed the state of the practice for bridge preservation through a literature search, consultations with contacts within the preservation community, and interviews with state-level bridge owners who use these technologies. Existing and historical activities undertaken by the city were also evaluated, and current needs were assessed. An informal risk analysis was used to prioritize activities and link the identified procedures with specific structures within the city. A field survey of bridges in Columbia was completed to help identify bridge preservation needs for particular bridges. These data were summarized and used to develop an implementable procedure for short-term (12 to 24 months after program implementation), mid-term (25 to 72 months after program implementation), and long-term (73 to 120 months after program implementation) actions to extend the life of bridges and reduce maintenance costs.

Key recommendations for the program include the identification and prioritization of low-cost preventive maintenance (PM) activities such as cleaning, periodic washing of bridges, and sealing of bridge decks that are currently in good condition. The identification of condition-based preservation needs through the implementation of a bridge preservation inspection program (BPIP) and the review of maintenance notes in the Missouri Department of Transportation (MoDOT) biennial inspection reports were recommended.

Funding Sources:
City of Columbia, Missouri ($19,427.00)
Midwest Transportation Center
USDOT/OST-R ($19,898.00)
Total: $39,325.00

Contract Number: DTRT13-G-UTC37

About the research

Accelerated bridge construction (ABC) has received significant research attention in recent years. For the most part, these research endeavors have focused on means and methods for decreasing impact to the traveling public during new bridge construction. At the same time, great opportunities exist to further reduce traffic impacts by decreasing construction time associated with bridge repair and rehabilitation.

Most bridges undergo several small and one or two major rehabilitations during their useful lives and decreasing the traffic impacts during these events could have significant societal benefits. Fortunately, many of the new construction concepts may be able to be adapted for use in rehabilitation scenarios. In still other cases, new means and methods may be needed.

This research completes a synthesis of available rehabilitation alternatives and solutions that could be used by practitioners to complete rapid rehabilitation projects. In some cases, these alternatives are adaptations of new construction methods and, in others, they are strictly for rehabilitation activities.

This synthesis provides a comprehensive summary of available solutions.

About the research

While levee embankments are the first line of defense for urban flooding, recent flooding events have revealed widespread slope instability of embankments around the country that can lead to levee failures. This work aimed to improve the slope stability of earthen levees by strengthening the soil through the use of a biologically-inspired technique called biocementation.
The major objective of this study was to determine the optimal and most practical biocementation method that results in the best performance of levee slopes under various flooding conditions.
A novel biocementation method called bacterial enzyme-induced calcite precipitation (BEICP) was tested. This method differs from the well-studied microbial-induced calcite precipitation (MICP) method mainly in the size of the biological agent (whole bacterial cell vs. enzyme), which influences the agent’s mobility in soils of different grain sizes.
The BEICP methods for soil strengthening were optimized in laboratory-scale column experiments. The optimized methods were then used to construct levees in an experimental flume system.
The results indicated that the BEICP treatment resulted in significant strengthening of the surface of the soil specimens, which were measured as increases in unconfined compressive strength. The strengthened samples were able to resist erosion for a longer time period under overtopping scenarios of water challenges with high water velocity in a flume. Therefore, BEICP offers a sustainable and economical method for treatment of soil surfaces to improve erosion resistance.
The results of this study will help mitigate flooding events that could cause major issues in transportation infrastructure and traffic safety.

Funding Sources:
Iowa State University ($82,233.00)
Midwest Transportation Center
USDOT/OST-R ($80,000.00)
Total: $162,233.00

Contract Number: DTRT13-G-UTC37

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.

Funding Sources:
Midwest Transportation Center
Smart Work Zone Deployment Initiative ($23,714.00)
University of Missouri – Columbia ($13,984.00)
USDOT/OST-R ($74,022.00)
Total: $111,720.00

Contract Number: DTRT13-G-UTC37

About the research

This research is exploring risk-based inspection (RBI) approaches to bridge inspection planning to better match requirements to inspection needs through engineering analysis.

Funding Sources:
Midwest Transportation Center
University of Missouri – Columbia ($87,544.00)
USDOT/OST-R ($78,992.00)
Total: $166,536.00

Contract Number: DTRT13-G-UTC37