The Saturation, Economic, and Energy Effects of Maturing Urban Roadway Networks

In the U.S., most urban roadway networks have been fully deployed. While outward growth still occurs, for the most part, the urban core roadway systems are no longer changing. This implies that there is a "maturing" of infrastructure. Yet at the same time, cities across the country are experiencing more and more congestion and many states and regions are unable to keep up with the long-term financing for rehabilitation to maintain high quality infrastructure. A saturated and deteriorating urban roadway system has the potential to compromise passenger and goods movement services thereby creating economic impacts for the city. New knowledge is needed to better understand i) how passenger and freight travel is effected by a roadway network that is becoming increasing saturated and ii) how this saturation may affect vehicle travel thereby impacting economic activity and changing transportation energy use. This project will develop a model of the historical growth of roadways from the beginning of Los Angeles (approximately 1900) to today by combining a statistical assessment of building ages in building assessor databases with geographic information system (GIS) analysis of roadway networks. To do this, to start with, a geospatial analysis will be developed that overlays the current building assessor databases at parcel scale, roadway network atlases, and travel analysis zones. Figure 1 shows the growth of each city based on building assessor databases. For each travel analysis zone, the modern day distribution of building ages will be determined. It is estimated that there will be roughly 20-50 buildings per travel analysis zone. Following, the oldest building vintages will be assigned to roadway links within the travel analysis zone under the assumption that buildings and roadways were deployed around the same time. For example, if for a particular zone it is found that the oldest buildings are from the 1930s era, that vintage will be assigned to the roadway links that service those buildings. Freeways and interstates will be assessed separately since they were likely constructed more systematically. The result will be a spatially explicit model of the growth of the roadway network over time. The model will be validated through the review of historical satellite photos. The infrastructure growth model will be joined with an assessment of changes in vehicle miles of travel (VMT). The project will start by using county-scale data for Los Angeles and historical travel demand model output at the travel analysis zone scale that has already been acquired from the Southern California Association of Governments. The analysis will start with Los Angeles because travel in that region has peaked (Federal Highway Administration (FHWA) 2012) and the infrastructure is mature. The VMT estimates will be compared to VMT projections that were developed in the past 10-20 years to assess how much travel was anticipated but did not occur. Elasticity estimates of fuel price, income, fuel economy, population, lane miles, and other factors will then be used to assess the potential supply and demand drivers of VMT changes for both passenger and freight. It is anticipated that there will be many elasticity estimates available and there will be a focus on region-specific past research. The project will also focus on developing an uncertainty assessment around the plethora of elasticity factors available to characterize in the best or worst case, how much those variables explain the changes in VMT. The results of the project can be used as a foundation for twenty-first century transportation infrastructure investment that balances environmental conditions with environmental impacts at a time when mobility dominated by personal vehicle travel may be changing. Improving the understanding of how passenger and freight activities have responded to the growth of cities will better position a recommendation to cities as to how they should invest in next generation infrastructure to better facilitate the growth that is expected in many major US metropolitan regions in the coming century.


  • English


  • Status: Completed
  • Funding: $70000.00
  • Contract Numbers:



  • Sponsor Organizations:

    Arizona State University, Tempe

    Tempe, AZ  United States 

    National Transportation Center @ Maryland

    1173 Glenn L. Martin Hall
    University of Maryland
    College Park, Maryland  United States  20742

    Research and Innovative Technology Administration

    University Transportation Centers Program
    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Project Managers:

    Chen, Xiqun

  • Performing Organizations:

    Arizona State University, Tempe

    Tempe, AZ  United States 
  • Principal Investigators:

    Chester, Mikhail

  • Start Date: 20150101
  • Expected Completion Date: 0
  • Actual Completion Date: 20151231
  • Source Data: RiP Project 39038

Subject/Index Terms

Filing Info

  • Accession Number: 01595748
  • Record Type: Research project
  • Source Agency: National Transportation Center @ Maryland
  • Contract Numbers: DTRT13-G-UTC30, NTC2015-SU-R-01
  • Files: UTC, RIP
  • Created Date: Apr 8 2016 1:00AM