Publications

Summary:
Urban freight denotes vehicle and commodity flows in an urban environment. These flows depend on a complex set of relationships among various stakeholders. In the last decades, urban freight has experienced an incredible pace of evolution, which has occurred due to various technological factors. One example is the ubiquity of internet access and the advance in information technology, leading to e-commerce adoption.

Summary:
The Norwegian Public Roads Administration, the Norwegian Geotechnical Institute, and SINTEF conducted a field test with a unmanned aerial system (UAS) with various instruments at the research station Fonnbu in Stryn. The purpose of the test was to evaluate the use of instrumented drones for monitoring and assessing avalanche danger. The instruments tested included optical and thermal imaging, laser scanning and ground-penetrating radar.

Summary:
The rapid rise of on-demand transportation and e-commerce goods deliveries, as well as increased cycling rates and transit use, are increasing demand for curb space. This demand has resulted in competition among modes, failed goods deliveries, roadway and curbside congestion, and illegal parking. This research increases our understanding of existing curb usage and provides new solutions to officials, planners, and engineers responsible for managing this scarce resource in the future.

Summary:
Moving freight is vital to our ability to live in cities and access goods — but who bears the costs of moving goods, and who benefits from the access that goods movement provides? These costs and benefits have not been borne equally. The last blog post revealed how urban freight is largely missing in discussions around transportation equity and accessibility. Freight delivers immense benefits to cities and residents.

Summary:
This paper presents a method for extracting transit performance metrics from a General Transit Feed Specification’s Real-Time (GTFS-RT) component and aggregating them to roadway segments. A framework is then used to analyze this data in terms of consistent, predictable delays (systematic delays) and random variation on a segment-by-segment basis (stochastic delays). All methods and datasets used are generalizable to transit systems which report vehicle locations in terms of GTFS-RT parameters.

Summary:
Fundamental diagrams describe the relationship between speed, flow, and density for some roadway (or set of roadway) configuration(s). These diagrams typically do not reflect, however, information on how speed-flow relationships change as a function of exogenous variables such as curb configuration, weather or other exogenous, contextual information.

Summary:
Capturing pedestrian exposure is important to assess the likelihood of a pedestrian-vehicle crash. In this study, we show how data collected on pedestrians using personal electronic devices can provide insights on exposure. This paper presents a framework for capturing exposure using spatial pedestrian movements based on GPS coordinates collected from accelerometers, defined as walking bouts.

Summary:
Is public charging a realistic option for urban freight? In Part 1, we focused our discussion on electrifying urban freight on grid capacity and installing the correct charger for the job. In this post, we continue the discussion by exploring an avenue for charging infrastructure: publicly available chargers.

Summary:
Predicting the stay time of private cars has various applications in location-based services and traffic management. Due to the associated randomness and uncertainty, achieving the promising performance of stay time prediction is a challenge. We propose an RNN-based encoder model to solve this problem, which consists of three components, i.e., an encoder module, an exception module, and an MLP dropout.

Summary:
While the number of deliveries has been increasing rapidly, infrastructure such as parking and building configurations has changed less quickly, given limited space and funds. This may lead to an imbalance between supply and demand, preventing the current resources from meeting the future needs of urban freight activities. This study aimed to discover the future delivery rates that would overflow the current delivery systems and find the optimal number of resources.

Summary:
Isolated communities are particularly vulnerable to disasters caused by natural hazards. In many cases, evacuation is the only option to ensure the population’s safety. Isolated communities are becoming increasingly aware of this threat and demand solutions to this problem. However, the large body of existing research on evacuation modeling usually considers environments where populations can evacuate via private vehicles and by using an existing road infrastructure.

Summary:
As urbanized populations and concentrations of activities increase, there is growing pressure in dense and constrained urban areas to unlock the potential of every public infrastructure element to address the increasing demand for public space. Specifically, there is a growing demand for space for parking operations related to the access to land use by people and goods.

Summary:
The meteoric rise in urban deliveries and the lingering societal effects of the Covid-19 pandemic are having dramatic implications for the future of business, climate, and cities. Together with our collaborators and subject matter experts from across the logistics landscape, we are creating a collective vision for the urban freight system in 2030 and we are excited to present it in a new blog.

Summary:
In this research we consider an approach for improving the efficiency and tightness of column generation (CG) methods for solving vehicle routing problems. This work builds upon recent work on Local Area (LA) routes. LA routes rely on pre-computing (prior to any call to pricing during CG) the lowest cost elementary sub-route (called an LA arc) for each tuple consisting of the following: (1) a customer to begin the LA arc, (2) a customer to end the LA arc, which...

Summary:
West Seattle (WS) is a part of the city of Seattle, Washington, but is located on a peninsula west of the Duwamish River. The West Seattle High-Rise Bridge serves as the primary connector between West Seattle and the rest of the city, carrying some 84,000 vehicles on average each day. On March 23, 2020, that high bridge was suddenly closed to all vehicle traffic for safety reasons due to greater-than-expected structural deterioration. The high bridge is now being repaired with a...