C2SMART researchers from Rutgers University and NYU designed and constructed a new “smart roadway testbed” along the cantilevered section of the Brooklyn-Queens Expressway (BQE) in Brooklyn, New York. This new testbed collect real-time data on truck loads using weigh-in-motion (WIM) sensors to measure their impact on the roadway.
Due to the ineffectiveness of current methods to stymie overweight trucks from using the BQE there is a need for a comprehensive and advanced enforcement plan to effectively reduce the volume of overweight trucks, which can be detected by WIM technology. The C2SMART research team also plans to work with NYCDOT and other agencies to bring WIM technology to other roadways for better enforcement of overweight trucks.
The goals of this effort include
- Deploying sensors on a live stretch of roadway with critical needs to monitor its condition
- Collecting and processing weigh-in-motion (WIM) data at different locations on the Brooklyn-Queens Expressway (BQE)
- Executing a quantitative data analysis of the roadway condition of the BQE
- Inform the decision-making process of the BQE Expert Panel tasked with evaluating construction alternatives
- Continued monitoring of the structure throughout its life
- Performance evaluation of automated enforcement practice in urban area
To achieve these objectives, the research methodology includes:
- Installation, calibration, and operation of WIM systems at two locations on the BQE triple cantilever corridor
- Collect data on the weights of vehicles, specifically trucks, traversing the corridor
- Conduct an impact study on the effects of large/illegally overweight trucks on the BQE, specifically the triple cantilever corridor
- Deployment of automated enforcement practice by integrating advanced sensors and system technologies
Sensor Design and Installation
The first step in installing the smart roadway testbed involved a selection of the two site locations that would house the WIM sensors. One segment was chosen to be along the BQE at Summit Street by the Waterfront District, and the other was at Pearl Street near DUMBO. The map below shows the rough location of these two WIM testbed locations. The blue segment in between the two segments is the triple cantilever section of the BQE, which has suffered the most from the impact of overweight trucks.
Researchers then performed a site evaluation to analyze the slope, roughness, and apparent cracks and potholes in accordance with ASTM E1318. The team chose the most appropriate roadway segments to maximize the accuracy of the WIM sensors – piezo polymer (PVDF) and piezo quartz (Quartz) WIM sensor. A field computer, data acquisition system, and uninterrupted power supply were designed for each WIM site.
Enclosures and junction boxes were attached to pre-existing metal sign frames along the highway, and some excavation was required in order to route cables to the locations where the sensors would be located in the roadway. Once the electronics were complete, the locations of the PVDF and Quartz sensors were marked and scored into the roadway. Each marked section of pavement was cut and the resulting slots were cleaned out.
Next, the WIM sensors were installed into the prepared crevices on the roadway. Grout was poured over the sensors and the surface was smoothened to be level with the existing roadway. For the quartz sensors a much wider slit in the roadway had to be prepared before insertion. Finally all of the sensor installation areas were finished with a polisher.
After installation was completed, a 5-axle semi-trailer truck (FHWA Class 9) with known axle weights traveled in each lane at a constant speed in order to determine the sensor calibration factor to process the weight measurement.
Continuing Data Collection
The WIM sensors installed by the researchers from NYU and Rutgers will help to inform design decisions regarding the future of the BQE, as well as any possible measures taken to limit the prevalence of overweight trucks on the BQE. Principal Investigator, Hani Nassif, and co-Principal Investigator and C2SMART Center Director, Kaan Ozbay, are also both members of the Brooklyn-Queens Expressway Expert Panel convened by the Mayor of New York City to craft a comprehensive plan for a redesign of the highway. The panel recently used research data including that collected by the researchers’ WIM sensors to make several proposals for the longterm longevity and decongestion of the BQE. Click here to learn more. Some of these recommendations included permanent lane reductions, designated and wide shoulders, and the development of a demand management plan to reduce BQE volumes by 15% or more.
The first batch of data collected from the WIM sensors showed that on the Queens-bound cantilevered section of the BQE 11.1% of trucks exceeded 80 kips. Higher live loads cause greater stress on the structure, shorten its lifespan, and jeopardize motorist safety. Continuing data collection from the sensors may also provide insights about the real-time condition of the roadway.
These sensors and data are part of the first phase of C2SMART’s planned urban testbed to cover the full stretch of roadway, and others in New York City, while collecting data on the resiliency of structures as well as other valuable data on the critical transportation link and its effects.