Making Work Zones Smarter: Data-Driven Decision Making

In honor of Work Zone Safety Awareness Week, the NJDOT Bureau of Research hosted a Lunchtime Tech Talk, “Making Work Zones Smarter: Data-Driven Decision Making” on April 11th.  Dr. Thomas M. Brennan from The College of New Jersey discussed his research using probe vehicle data – that is, anonymous vehicle speed data — to inform the development of work zone mobility performance measures and “Smart Work Zone” congestion management strategies.

Dr. Brennan described how probe vehicle data can be applied to work zone planning.

An important goal of Dr. Brennan’s research has been the development of mobility performance measures that align with the transportation agency’s goals to improve reliability and speeds and diminish delays, queuing, and user costs.   In his talk, Dr. Brennan demonstrated how probe vehicle data collected from a public agency or commercial vendor can be converted from its raw form into mobility performance measures and compelling visualizations for decision-makers to use in formulating appropriate work zone policies and procedures.

He outlined a case study design framework and the steps needed for analyzing work zone effects on mobility performance measures. He described the types of information needed to conduct a work zone mobility audit, including traffic flow and work zone activity data. Using anonymous vehicle speed data, information about traffic slowdowns within the designated area can be gathered.   With enough data points stored over time – and with the appropriate performance measures and visualizations – it is possible to evaluate whether a work zone is increasing congestion as a result of the roadway system, as a result of the type of construction being undertaken, or some combination of both.

Dr. Brennan described the research he has performed in work zones in both Indiana and New Jersey, including an example of road closures of Route 80 in New Jersey. He found that, by gathering speed data alone, one could make an informed observation on when road work was being done and the effects on the surrounding road system. The data measured the impacts of work zones before, during, and after a project’s completion, showing the total “life-cycle” effect of a work zone.

Dr. Brennan noted several types of decisions that state agencies must make to implement a data-driven approach to work zone management.   For example, state agencies will need to select the types of work zones to apply the information, determine appropriate performance measures, define appropriate criteria for “congestion” thresholds, establish the right level of geographic detail and frequency for monitoring and measuring performance, and identify strategies to manage poorly performing work zones.  High-level agency strategies must also be put in place for efficiently archiving the various data that is collected, defining appropriate agency-wide performance measures and standards, and whether to incentivize contractors based on mobility performance measures, among other considerations.

Visualization of performance thresholds for speed, delays travel times.

During the course of the talk, Dr. Brennan highlighted various ways in which probe vehicle data can be used to characterize the reliability, resiliency and congestion at the regional and granular level to inform work zone planning. He hopes to use traffic flow data and work zone activity data to develop a comprehensive guide on how best to predict future congestion. Such data would combine the type of work zone (e.g., lane closures, patching, ramp closures, etc.) with archived data showing how previous similar events had affected the road system. This information could be used to provide agencies with alternative designs for future work zones, and provide drivers with alternative routes, thereby improving the safety and capacity of a work zone for workers and travelers alike.

Resources

Brennan, T. (2019).  Making Work Zones Smarter: Data Driven Decision Making (Presentation)

Brennan, T. M., Venigalla, M. M., Hyde, A., & LaRegina, A. (2018). Performance Measures for Characterizing Regional Congestion using Aggregated Multi-Year Probe Vehicle Data. Transportation Research Record, 2672(42), 170–179. https://doi.org/10.1177/0361198118797190

Remias, S., T. Brennan, C. Day, H. Summers, E. Cox, D. Horton, and D. Bullock (2013). 2012 Indiana Mobility Report: Full Version.  https://docs.lib.purdue.edu/imr/4/

 

 

Orthotropic Bridge Deck Design

Steel orthotropic deck

On July 9th, Dr. Sougata Roy discussed the benefits of using orthotropic bridge decks, focusing on their design, fabrication, and construction. He addressed a room of NJDOT employees, highlighting significant projects that have utilized orthotropic bridge decks, including the first such bridge designed by NJDOT.

An orthotropic bridge deck is one in which a steel deck plate is supported by longitudinal ribs and transverse crossbeams. The ribs and crossbeams give the deck different stiffness in the transverse and longitudinal directions, allowing it to distribute weight effectively.

Dr. Roy first posited the advantages of using these bridge decks, emphasizing their light weight and structural efficiency, and their estimated life span of over 100 years. Orthotropic bridge decks are lighter due to the reduced need for concrete, which minimizes the total dead load carried by the rest of the structure. Estimates are that up to 25 percent of a bridge’s total mass can be saved by reducing the deck weight, and those weight reductions can extend to cables, towers, piers, and so forth. Orthotropic decks are prefabricated and their modular form allows for accelerated bridge construction and higher quality control. The bridges can be erected more quickly, thus minimizing the impact on New Jersey’s motorists. The maintenance requirements for orthotropic bridges are expected to be much lower as there would be no need to re-deck the bridges every few decades. While Dr. Roy acknowledged that there are high initial construction costs associated with orthotropic bridges due to the complex welds involved, such costs would be offset by the lower maintenance costs over the life of the bridge.

Dr. Roy suggested that the orthotropic bridge deck design could help address some of the state’s greatest transportation infrastructure needs related to bridge condition, maintenance, as well as overall traffic congestion. To demonstrate this, Dr. Roy used data from the Route 7 Wittpenn Bridge between Kearny and Jersey City, which is the first bridge constructed by NJDOT to use an orthotropic bridge deck.

Bridge deck in transit to New Jersey

The 300-foot deck was shipped in one piece via the Panama Canal from Portland, Oregon and arrived at the Wittpenn Bridge in July, 2017. For an illustrated depiction of the Wittpenn Bridge deck’s trip to Kearny, see Oregon to New Jersey: The Journey of New Jersey Department of Transportation’s First Orthotropic Deck.

The current work on the bridge is proceeding quickly as the steelwork for the bridge is less impacted by cold weather than a typical concrete bridge deck would be. The new bridge will be twice as high as the current Wittpenn, and will feature wide lanes and shoulders.

Dr. Sougata Roy presents Cost Effective Design for Orthotropic Bridge Decks

For related information, please view the report, Design and Fabrication of Orthotropic Deck Details. The objectives of the research were to verify the design and fabrication of the orthotropic deck details proposed for the lift bridge, for infinite fatigue life. Multi-level 3D finite element analyses (FEA) of the proposed deck were performed to determine the critical stresses at the connections, the corresponding load position, and the deck specimen. To develop cost-effective connection details, three variations of rib-to-floor beam and rib-to-deck plate connection details, including the influence of different fabrication parameters, were explored in full-scale, small-size mockups. Subsequently, the infinite life fatigue performance of the connection details were evaluated by laboratory testing of a full-scale prototype. The fatigue testing was conducted under simulated rear tandem axle loading of the American Association of State Highway and Transportation Officials (AASHTO) fatigue truck with adequate boundary condition. The prototype testing was runout after 8 million cycles, verifying the infinite life fatigue performance of the deck design.

 

 

 

 

RABIT: Automated Condition Assessment of Concrete Bridge Decks by Robotic System

Dr. Nenad Gucunski speaking at a recent Lunchtime Tech Talk!

The April 6, 2018 Lunchtime Tech Talk featured Professor Nenad Gucunski, Director of the Center for Advanced Infrastructure and Transportation (CAIT) Infrastructure Condition Monitoring Program and chair of the Department of Civil and Environmental Engineering at Rutgers University. Dr. Gucunski spoke to a full room of NJDOT employees about the benefits of non-destructive bridge evaluation (NDE) technologies, as well as the latest advancements in the field.

The benefits of NDE are many, but ultimately the value is realized by its ability to help bridge owners make better-informed decisions regarding maintenance, repair, and rehabilitation of vital infrastructure.  New Jersey serves as the perfect laboratory for the development of such technologies, given the myriad of aging bridges in the state and the congestion that demands bridge evaluation be done quickly, but as safely as possible. Dr. Gucunski highlighted two of CAIT’s breakthrough platforms to achieve these goals, the RABIT™ and the BEAST.

Equipped with ground penetrating radar, GPS, digital cameras, and other instrumentation to measure electrical resistivity and ultrasonic waves, the RABIT™ is a robot that can single-handedly perform in-depth bridge inspections. With these tools, the RABIT™ provides quantitative assessment of concrete bridge decks and presents the data in an intuitive manner with graphs that provide a comprehensive picture of bridge health. According to Professor Gucunski,

the RABIT

The RABIT

“In the past, we didn’t have a way to compile information on delamination, degradation, corrosion, precise location, visual, or load stress data all at once. Not only does RABIT™ help us validate data collected from individual machines, but it forms a meaningful picture of what’s happening inside the bridge deck in real time to help us arrest deterioration.”

This robot not only increases the speed in which data are collected and analyzed, but reduces the cost and traffic congestion associated with doing so. Most importantly, it improves the safety for workers who are no longer required to perform lengthy inspections in high traffic areas. Dr. Gucunski presented the results of various NDE surveys that had been completed by the RABIT™ from around the country, highlighting the demand and efficiency of such technologies. Furthermore the robot is able to not only evaluate the state of bridges, but can also perform minor rehabilitation repairs. When the robot sees delamination occur below the surface, it has the ability to bore a hole into the bridge and flood the cracking with a sealant that NJDOT employee Dr. Giri Venkiteela was instrumental in creating.

Dr. Gucunski also focused the spotlight on the BEAST, the next level of bridge deck evaluation. While the RABIT™ can be used to evaluate the current bridge inventory through safe and non-destructive means, the BEAST tackles the problem in a different way: by actively speeding up the impact and deterioration of bridges to give researchers a look how bridge systems will fare over in the future. The BEAST tests sample bridge with spans of up to 50 feet long and 28 feet wide using rapid-cycling temperature extremes, simulated precipitation, and a loading device that inflicts the same kind of beating as 24-7 heavy truck traffic. The BEAST “compresses time” and demonstrates decades of deterioration after only a few months. The BEAST offers a unique insight on the future performance of materials and structural components, supplying bridge owners information that could previously only be realized after decades of wear and tear. This technology not only helps with the design of bridges that have not yet been built, but  allows for a better understanding of how current bridges may fail and can identify the best rehabilitation and preservation techniques.

the BEAST

The BEAST

New Jersey’s infrastructure is amongst the oldest in the country, with over a third of our bridge systems deemed structurally deficient or in need of repair. Since it is logistically and financially impossible to repair every single bridge, these two technologies help expand the lifespan and performance of the bridges we have today.

Resources

View the presentation: Gucunski, N. (2018).  RABIT: Automated Condition Assessment of Concrete Bridge Decks by Robotic System

Below is a short video of the RABIT (Robotics Assisted Bridge Inspection Tool) in action (no sound).

Tech Talk Recap: Smart Cities and Transportation with Kenneth Leonard

On February 20, 2018, the fifth event in the Lunchtime Tech Talk series took place and featured speaker Kenneth M. Leonard, Director of the U.S. Department of Transportation Intelligent Transportation Systems (ITS) Joint Program Office. Leonard spoke to a full crowd of attendees including NJDOT personnel. Leonard, a recognized leader in the field of ITS, focused his presentation on the USDOT Smart Cities Challenge and the way connected cities and communities could become “smart”.

The Smart Cities Council has deemed a Smart City to be one that uses information and communications technology (ICT) to enhance its livability, workability, and sustainability. Leonard explained that connected infrastructure technology can support a smart community through such things as connected vehicles, sensor-based intelligent infrastructure, smart grids, data management and urban analytics, among others. He shared an example of components of a connected city, citing that “Transportation is critical to making a city work—in commuting to work, education, entertainment, as well as shipping and receiving products”.

Leonard highlighted the Columbus, Ohio demonstration project where a $140 million investment in Smart Columbus will create the Columbus Connected Transportation Network, which will include integrated data exchange, enhanced human services, and electronic vehicle infrastructure.

Leonard suggests that smart communities produce desired outcomes that include safety enhancements and efficiency in services. The Smart Columbus project has measurable outcomes, such as: enhanced safety through reduced truck accidents, increased mobility through minimized travel times, improved employment opportunity by reaching underserved communities, and improved air quality from reduced truck congestion and increased access to EV charging stations.

Columbus was selected as the 2016 winner of the USDOT Smart Cities Challenge competition, which included the participation of 77 cities nationwide. To read about the Smart Cities Challenge, please visit: https://www.transportation.gov/smartcity

Resources

View the presentation: Leonard, K. (2018). Smart Cities and Transportation.

You can watch a video of the presentation below.

Smart Cities and Transportation

Lunchtime Session

Kenneth M. Leonard, Director of the U.S. Department of Transportation (USDOT) Intelligent Transportation Systems Joint Program Office (ITS JPO), will share the lessons learned so far from the Smart City Challenge. In December 2015, the USDOT launched the Smart City Challenge, asking mid-sized cities across America to develop ideas for an integrated, first-of-its-kind smart transportation system that would use data, applications, and technology to help people and goods move more quickly, cheaply, and efficiently. By challenging American cities to use emerging transportation technologies, the Smart City Challenge seeks to spread innovation through a mixture of competition, collaboration, and experimentation and encourage communities to envision bold new solutions that could change the face of transportation in US cities.

Through the Smart City Challenge, USDOT committed up to $40 million to one winning city, Columbus, Ohio. USDOT estimates that cities have leveraged an additional $500 million in private and public funding to help make their Smart City visions real. USDOT subsequently announced an additional $65 million in grants to support community-driven advanced technology transportation projects in cities across America, including four of the finalists in the Smart City Challenge. Mr. Leonard will discuss how these innovative solutions could help communities meet the challenges of today and tomorrow.

The USDOT ITS program focuses on intelligent vehicles, intelligent infrastructure and the creation of an intelligent transportation system through integration with and between these two components. The Federal ITS program supports the overall advancement of ITS through investments in major research initiatives, exploratory studies, and a deployment support program including technology transfer and training.

Date: February 20, 2018
Time: 11:45 am-1:00 pm
Location: NJ DOT Foran Bulding Training Room #1, 1035 Parkway Avenue, Trenton, NJ 08625

Due to popular demand, this event will be held in the NJ DOT Multipurpose Room, 1035 Parkway Avenue, Trenton, NJ 08625

Please register at: https://smartcities-transportation.eventbrite.com

AICP & NJ PE credit are available.

Getting through the Green: Smarter Traffic Management with Adaptive Signal Control

NJDOT Assistant Commissioner for Transportation Systems Management, C. William Kingsland, spoke about Adaptive Signal Control (ASCT) during the third Lunchtime Tech Talk hosted by the Bureau of Research on November 29, 2017.

The Federal Highway Administration (FHWA) defines ASCT as technologies that capture current traffic demand data to adjust traffic signal timing to optimize flow in coordinated traffic signal systems.  FHWA established ASCT as one of its Every Day Counts Round One initiatives in 2011-2012. New Jersey has implemented ASCT through the work of the Traffic Management Systems unit.

Assistant Commissioner Kingsland pointed out that commuters anticipate the time it will take for their typical commute routine and that reliability in travel time is important; people do not like fluctuation in the time it takes to get from A to B. When there is reliability of travel time, people’s expectations are met. ASCT effectively reduces congestion and fuel consumption, thus reducing complaints and frustration.

The ASCT system continuously learns based upon the traffic that is out there and will respond to changes in traffic patterns. Thus, the ability to adapt to unexpected changes in traffic conditions will produce improved mobility through a given area. Furthermore, as connected vehicles become more prominent, the system has the ability to gather information through Vehicle-to-Infrastructure communication and provide timely data of vehicle spacing and signal timing.

Assistant Commissioner Kingsland also provided some highlights about COAST- NJ, the management system developed by AECOM and the New Jersey Institute of Technology that is used to help decide where the ASCT systems will be placed. Using quantitative analysis, the tool ranks sections of corridors based on severity of congestion, variability of congestion, signal spacing, and traffic volume. COAST -NJ provides a classification system scoring process that encompasses 2,562 signalized intersections, 297 signalized arterial corridors, and 56 signal systems. It was officially released for use in March 2017.

During the Q&A portion of the Tech Talk, a member of the audience asked whether the system retains the collected traffic flow information to be able to look back to a certain date and time. The answer is that yes, it can. The issue, however, becomes length of records retention and where to store all of this information over the long-term.

In NJ, some of the NJDOT project locations with ASCT are along Route 130 (MP 69.79 to 74.51) with 15 intersections tied in; Route 168 (MP 6.79 to 9.72) with 11 intersections; and Route 32 (MP 0.0 to 1.20) with two intersections. Mr. Kingsland noted that Route 18 South in New Brunswick to East Brunswick is about to go online

Other agencies are also implementing ASCT. While not a NJDOT project, in the Meadowlands area there are 140 intersections tied into one ASCT system area managed by the Meadowlands Commission.

Mr. Kingsland was asked if rural areas with large distance between signals could possibly have cameras placed at intermediate sections between intersections. Kingsland replied that they certainly could, but the cost of such projects is prohibitive at this point in time.

Due to popular demand, Assistant Commissioner Kingsland presented this Tech Talk again on January 29, 2018.

Resources

Kingsland, W. (2017). Adaptive Signal Control—Getting Through The Green (Presentation).

CIPGA Works!

The Capital Investment Planning and Grants Administration (CIPGA) Works! Group hosts lunchtime talks on a variety of topics to brief staff on the mission, roles, and responsibilities of operating units.

Recent presentations are available below.

For more information, visit the CIPGA Works! site on NJDOT intranet.

Bicycle & Pedestrian Programs

Bureau of Research

Capital Investment Planning & Development

Capital Program Coordination

Environmental Resources

Freight Services

Local Aid & Economic Development

Maritime Resources

Multimodal Grants, Programs & Aeronautics

NJ State Transportation Innovation Council

Park & Ride Program

Performance Management

Roadway Data & Crash Records Unit

Statewide Planning

Technical Analysis Unit

Traffic & Technology Section

Transportation Data & Safety

More than a Pretty Face(ade): Meeting Safety and Historic Requirements in Concrete Barriers

Recently, the Rutgers Infrastructure Monitoring and Evaluation (RIME) Group, a multi-modal transportation infrastructure research and education facility, was tasked to develop an open-faced concrete balustrade design that meets the aesthetic requirements of the Historic Preservation Office (HPO) and the safety requirements of FHWA. The RIME research team used computer simulation—detailed finite element analysis via LS-DYNA—and full-scale crash testing according to MASH TL-4 safety performance criteria. The result was a historical and crash-tested parapet for the Pulaski Skyway that can be used to replace similar barriers nation-wide while maintaining safety and retaining its aesthetic shape.

Dr. Hani Nassif, Professor of Civil and Environmental Engineering at Rutgers University and the lead Principal Investigator, spoke about the project at NJDOT’s Bureau of Research Lunch Session, on Monday, July 17. His talk, which is part of an ongoing Tech Talk series, gave an overview of the design, modeling and crash testing of open-faced concrete barriers, a study which started three years ago, spurred by a 2011 change in AASHTO requirements adopted by FHWA. This was the first completed study with these new requirements, partly due to cost—it costs a minimum of $250,000 to complete each crash test—and partly because the HPO was reluctant to replace parts of the Pulaski Skyway until recently preferring to preserve and redesign the current balustrade.

The study had a significant modeling component conducted using the LS-DYNA simulation program, a program that analyzes the nonlinear response of structures. Next, RIME did a parametric study before the physical testing began. The function of the new barrier is to bring the truck back into the lane, so the physical tests had a box truck, pickup truck, and sedan hit the barrier joints specifically, but at different angles. In all three instances, the vehicles were controlled and redirected back into traffic.

The result was that the testing was successful and met MASH requirements and the new barrier is in queue for approval by the FHWA. Other conclusions from the study are that dynamic finite element modeling is a good tool, and a computer simulation validated with full-scale test data can replace a full-scale test.  Dr. Nassif noted that one future task is to design a guardrail transition terminal, checking the barrier with MASH TL5 using LS DYNA Model and then crash test if the models provide acceptable results.

The Lunchtime event, the second installment of the Tech Talk series, was well-attended with about 40 NJDOT and industry professionals.  For those present, the event provided opportunities for back and forth Q&A, including a discussion about damage to the infrastructure based on the test barrier specifications. One attendee commented that he was looking forward to follow-up on the project regarding FHWA’s response.

The Rutgers Infrastructure Monitoring and Evaluation (RIME) Group is a multi-modal transportation infrastructure research and education facility that focuses on structural health monitoring, advanced concrete materials, finite element analysis, traffic and transportation analysis, and life cycle cost analysis.   

The Project Team included:
Lead PI: Hani Nassif, Ph.D., Rutgers University
Co-PIs: Malcolm Ray, PE, Ph.D., Chuck Plaxico, Ph.D., Roadsafe LLC
Research Affiliates: Andrew Wassef, Dan Su, Ph.D., Chaekuk Na, Ph.D.
Giri Venkiteela served as NJDOT Project Manager

Resources

Nassif, H. (2017). More than a Pretty Face(ade): Meeting Safety & Historic Requirements in Concrete Barriers (Presentation).

Autonomous Cars and Our Disrupted Future

On May 3, 2017, the Tech Talks lunch series was launched with a presentation from Dr. Scott Le Vine on “The Autonomous Car and Our Disrupted Future.” Held in the multi-purpose room at NJDOT’s headquarters, the event was well-attended, drawing a multi-disciplinary audience of some 50 employees from NJDOT. The session provided an opportunity to receive continuing education credits—Professional Development Hours (PDH) credits for professional engineers and AICP maintenance credits for planners.

In his 50-minute talk, Dr. Le Vine, an Assistant Professor in Urban Planning at the State University of New York (SUNY) at New Paltz, described the current “state-of-play” as to research on the development, implementation and effects of automated vehicles. He noted that major car manufacturers already sell higher-end vehicles equipped with active blind spot assistance, automated braking, self-parking, lane-departure warning and variable speed-cruise controls. The adoption of these autonomous-car technologies may portend a driverless vehicle future, but there are still many barriers—technological, infrastructural, legal, economic, and human, among others—to reaching a highly or fully automated driving system environment.

Dr. Le Vine’s talk covered a good deal of instructive ground. He explained the building blocks of autonomous driving which require a car equipped with sensor systems as well as the capability to process its readings so that it can identify where it is and what is happening around it. There are also several levels of automation—reflecting different levels of customer preference and human driver monitoring of the vehicle—and cautioned that the prospects and timing for a fully automated vehicle operating with near-100% reliability are highly uncertain.

In his remarks about litigation and liability, he discussed the “current rules of the road” and the legal standard, “Assured Clear Distances Ahead” (ACDA), for safe-traveling distances between vehicles:

“When an automobile approaches from the rear, he or she is bound to… exercise reasonable care to avoid colliding with the other vehicle.  The driver of a forward vehicle has a right superior to that of a following vehicle’s drive.”

He posited that autonomous vehicle (AV) designers may maximize ACDA-compliance both to ensure safety and minimize their potential legal liability. While individual drivers today may choose to operate without keeping safe distance to cars ahead, AV manufacturers would be compelled to program vehicles to operate more cautiously to avoid legal liabilities. Interestingly, programming AV vehicles for ACDA compliance could have adverse traffic congestion consequences. Still, as the size of the overall AV fleet increases, or where AV vehicles could congregate in platoons, there is a potential for AV vehicles to closely follow which could improve lane capacity and reduce congestion.

Both in his talk and in the issues raised during the Q&A session with participating NJDOT staff, Dr. Le Vine touched upon possible effects, forms of risk, and high levels of uncertainty in AV adoption. These uncertainties complicate the picture today and warrant scenario-type exercises for planners. These include issues of terror and security, data privacy and software hacking; fleet age and turnover; market penetration and rates of adoption of AVs; regional land use patterns (e.g., sprawl vs. centralizing patterns) and total VMT effects; competitive shares for taxi, shared mobility and transit services; traditional car ownership models or leasing arrangements from auto suppliers to manage rapid advancements in technology and obsolescence; location and role of parking; design of streets and drop-off points; segregation or co-existence of AVs with pedestrian and cyclists; etc.

Levels of Automation

Click to enlarge / Source: Scott Le Vine

Despite the uncertainties, Dr. Le Vine made clear that significant R&D investments and entrepreneurial bets are being made on automated vehicles. Many sectors and stakeholders are motivated to advance toward this new frontier in transportation, including: auto industry and original equipment manufacturers (OEMs), information technology companies (IT), transport network companies (TNCs), shared mobility and transit, and goods movement sector. Governments at all levels must get better educated and better prepared to facilitate this future as well as mitigate the truly transformative effects of this new technology.
Dr. Le Vine’s research presentation is available on the Bureau of Research’s website devoted to the Technology Transfer Program. His presentation contains links to several other research articles on the topic that he has prepared.

Resources

Le Vine, S. (2017). The Autonomous Car and our Disrupted Future (Presentation).

Le Vine, S., Zolfaghari, A., & Polak, J. (2015). Autonomous cars: The tension between occupant experience and intersection capacity. Transportation Research Part C: Emerging Technologies, 52, 1-14.

Pawlak, J., Le Vine, S., Polak, J., Sivakumar, A., & Kopp, J. (2015). ICT AND Physical Mobility: State of knowledge and future outlook. Institute for Mobility Research, Imperial College London, UK.