Smart Cities Center

Method and Apparatus for Next Token Prediction Based on Previously Observed Tokens

Pietrobon, Davide
Lewis, Andrew
Macfarlane, Jane
Berry, Robert
2018

An approach is provided for next token prediction based on previously observed tokens. The approach involves receiving an observed time series of tokens, wherein each of the tokens represents an observed data pattern. The approach also involves adding a most recent token from the observed time series of tokens into a variable token set. The approach further involves processing a historical token set to determine a historical token sequence comprising the variable token set followed by a next token. The approach further involves recursively adding a next most recent token from the...

Method and Apparatus for Providing Semantic-Free Traffic Prediction

Pietrobon, Davide
Lewis, Andrew
Macfarlane, Jane
2017

An approach is provided for semantic-free traffic prediction. The approach involves dividing a travel-speed data stream into a plurality of travel-speed patterns. The travel-speed data stream represents vehicle travel speeds occurring in a road network. The approach also involves representing each of the plurality of travel-speed patterns by a respective token. The respective token is selected from a dictionary of tokens representing a plurality of travel-speed templates determined from historical travel-speed data. The approach further involves matching a sequence of the respective...

Mobiliti: A Digital Twin for Regional Transportation Network Design and Evaluation

Macfarlane, Jane F.
Babur, Ismaeel
Grieves, Michael
Hua, Edward Y.
2024

Mobiliti is introduced as a foundation for a Digital Twin for managing transportation systemsTransportation systems across metropolitan regions and for planning and designing urban networks. Regional transportation systemsTransportation systems consist of interconnected subnetworks, each governed by different municipalities. Although localization simplifies analysis, transportation projects must be evaluated within the context of the larger regional network due to their potential impacts on overall network performance. The computational challenges of simulating metropolitan networks are...

Mobiliti: Scalable Transportation Simulation Using High-Performance Parallel Computing

Chan, Cy
Wang, Bin
Bachan, John
Macfarlane, Jane
2018

Transportation systems are becoming increasingly complex with the evolution of emerging technologies, including deeper connectivity and automation, which will require more advanced control mechanisms for efficient operation (in terms of energy, mobility, and productivity). Stakeholders, including government agencies, industry, and local populations, all have an interest in efficient outcomes, yet there are few tools for developing a holistic understanding of urban dynamics. Simulating large-scale, high-fidelity transportation systems can help, but remains a challenging task, due to the...

Quasi-Dynamic Traffic Assignment using High Performance Computing

Chan, Cy
Kuncheria, Anu
Zhao, Bingyu
Cabannes, Theophile
Keimer, Alexander
Wang, Bin
Bayen, Alexandre
Macfarlane, Jane
2021

Traffic assignment methods are some of the key approaches used to model flow patterns that arise in transportation networks. Since static traffic assignment does not have a notion of time, it is not designed to represent temporal dynamics that arise as vehicles flow through the network and demand varies through the day. Dynamic traffic assignment methods attempt to resolve these issues, but require significant computational resources if modeling urban-scale regions (on the order of millions of links and vehicles) and often take days of compute time to complete. The focus of this work is...

Simulating the Impact of Dynamic Rerouting on Metropolitan-scale Traffic Systems

Chan, Cy
Kuncheria, Anu
Macfarlane, Jane
2023

The rapid introduction of mobile navigation aides that use real-time road network information to suggest alternate routes to drivers is making it more difficult for researchers and government transportation agencies to understand and predict the dynamics of congested transportation systems. Computer simulation is a key capability for these organizations to analyze hypothetical scenarios; however, the complexity of transportation systems makes it challenging for them to simulate very large geographical regions, such as multi-city metropolitan areas. In this article, we describe enhancements...

Temporal Sampling Constraints for GeoSpatial Path Reconstruction in a Transportation Network

Macfarlane, Jane
Xu, Bo
2017

In this paper, we address the problem of recovering traveled geospatial paths on a transportation network from time sampled location traces. Determining the proper sampling rate for path reconstruction has not traditionally been addressed ahead of the collection process. Instead various uncertainty models have been created and tuned to estimate possible geospatial paths from an existing set of location measurements. This paper suggests that the geospatial road density sets a fundamental constraint on the sampling frequency. The result shows that a sufficient sampling rate is determined by...

The Transforming Transportation Ecosystem — A Call to Action

Macfarlane, Jane
2019

The transportation landscape is in transition. Rising congestion, failing infrastructure, changing behaviors, adapting to a more inclusive definition of mobility, the desire for cleaner and more efficient engines, and grappling with the role of autonomous vehicles and drones, to name just some of the factors, demands that we take a fresh approach to designing for mobility. Yet the rapid pace of technology development is creating emerging trends that are driving change faster than our ability to model, design, and manage them. This could potentially result in undesirable economic,...

Transfer Learning with Graph Neural Networks for Short-Term Highway Traffic Forecasting

Mallick, Tanwi
Balaprakash, Prasanna
Rask, Eric
Macfarlane, Jane
2021

Large-scale highway traffic forecasting approaches are critical for intelligent transportation systems. Recently, deep- learning-based traffic forecasting methods have emerged as promising approaches for a wide range of traffic forecasting tasks. These methods are specific to a given traffic network, however, and consequently they cannot be used for forecasting traffic on an unseen traffic network. Previous work has identified diffusion convolutional recurrent neural networks, (DCRNN), as a state-of- the-art method for highway traffic forecasting. It models the complex spatial and temporal...

New Aggregation Strategies to Improve Velocity Estimation from Single Loop Detectors

Coifman, Benjamin
Lee, Zu-Hsu
2000

Loop detectors are the preeminent vehicle detector for freeway traffic surveillance. Although single loops have been used for decades, debate continues on how to interpret the measurements. Many researchers have sought better estimates of velocity from single loops. The preceding work has emphasized post-processing techniques. Although rarely noted, these techniques effectively seek to reduce the bias due to long vehicles in measured occupancy and flow. This paper presents a different approach, using a new aggregation methodology to estimate velocity and reduce the impact of long vehicles...