Documents in the Category: all

Statewide Raised Median Toolkit

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The Utah DOT has created an impressive Statewide Raised Median toolkit.

The purpose of the Assessment Tool is to guide decision-makers to determine the appropriateness and potential benefits of raised medians on specific roadway corridors. Potential users of this tool include planners, design engineers, traffic engineers, and project managers.


Research-based evaluation to determine suitability


Guidance for community discussions


Resources to support decisions

AM18 Poster Hitesh Chawla

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Crash Risk and Access Spacing on Two-Lane and Multi-Lane Highways

Hitesh Chawla; Peter T. Savolainen, Ph.D., P.E.



Effective access management is essential to mitigating traffic crash risks. Most of the crashes occurring near access points are a result of conflicts between multiple vehicles. This motivates the development of guidelines for access spacing. To this end, this study evaluated the relationship between crash risk and access point spacing on two-lane and multi-lane highways across the state of Iowa.

AM18 Poster Beiia Zhang

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Access Management to Reduce Wrong-Way (WWD) Driving on Alabama Divided Highways

Beijia Zhang


A divided highway is considered as a highway with physical separation, and the side streets are its access points in this study.

WWD crashes are more possible than other kinds crashes to result in fatal or incapacitating injuries. The majority of previous studies are focused on freeways instead of divided highways.

112 WWD crashes were identified in Alabama divided highways from 2009 to 2013.

AM18 Poster Dan Xu (1st Place Poster Award)

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Interchange Deceleration Lane Design Based on Naturalistic Driving Speed and Deceleration Rates

Dan Xu (1st Place Poster Award Winner) and Chennan Xue

(Poster updated 8/1/2018)

The Green Book provides the minimum lengths of deceleration lanes. The length recommendations provided by the 2011 edition are similar to the documents published in 1965, which were based on the data collected in the 1930s and had not been updated. (Fitzpatrick et al., 2012; Abdelnaby, 2014) Data was obtained from NDS dataset, including Video and Time Series Report.

AM18 Poster Md Atiquzzaman (2nd Place)

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Access Control and Geometric Features at the Interchange Terminals with a large number of Wrong-Way Incidents: Case Studies in Alabama

Md Atiquzzaman (Tie for 2nd Place Award)

Although wrong-way driving crashes are rare, they draw a lot of attention due to their severe outcomes. Two interchange terminals were monitored by video camera for 48 hours on a typical weekend. The two locations experienced 10 and 17 WWD incidents.


AM18 Poster Chennan Xue, Dan Xu

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A Probabilistic Model to Predict Intermittent Sight Distance Obstruction at Unsignalized Intersections on High-Speed Rural Divided Highways

Chennan Xue and Dan Xu

Minor-road left-turn vehicles’ views are likely to be blocked by major-road right-turn vehicles on the conventional right-turn lane at unsignalized intersections.


Extent and Impacts of the VA-DOT Exception Process for Access Management Design Standards

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The Virginia Department of Transportation (VDOT) has released a report that addresses Virginia’s standards and exemption processes for commercial entrance spacing. This report also observes the extent to which commercial access exceptions are used in Virginia, and the impact on crashes at these sites. The previous VDOT Road Design Manual details requirements that new commercial entrances meet certain minimum spacing standards, though landowners may request exemptions. 

NCHRP 875 Safety Impacts of Intersection Sight Distance

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NEW! NCHRP Research Report 875: Guidance for Evaluating the Safety Impacts of Intersection Sight Distance is a resource for practitioners involved in the planning, design, operations, and traffic safety management of stop-controlled intersections. It provides information on how to estimate the effect of intersection sight distance (ISD) on crash frequency at intersections and describes data collection methods and analysis steps for making safety informed decisions about ISD.

Sponsorship Opportunities

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We are happy to announce that – for the first time ever – sponsorship of the National Access Management Conference is available. These sponsorships help support the work of this committee to spread the word about how access management improves our transportation system by saving lives and improving mobility.

Quite a variety and levels of sponsorship are available, as indicated in the sponsorship form.  

You can help support the National Access Management Conference as a

Combined AMAG & AM Manual

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 TRB's newest publications on access management draw on national and state research to respond to the need for a more coordinated approach to transportation and community design that preserves the safe and efficient movement of peoples and goods, provides supporting networks in developed areas, and reinforces desired urban form.

FDOT Trip Generation Recommendations

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FDOT has the responsibility of maintaining the State’s roadway system. As a result, it is FDOT’s responsibility to monitor the traffic impacts of new development along the State Highway System. In response to the ever changing economic climate following the downturn of the economy, FDOT saw the need to assess the validity and applicability of trip generation and internal capture practices in Florida.

MS DOT Synthesis of J-Turn Design Standards and Criteria

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Transportation professionals today are faced with the challenge to meet the mobility needs of an ever increasing population with limited resources. One potential treatment to mitigate congestion and safety problems at rural expressway intersections, while trying to avoid signalization or grade‐separation, is the J‐Turn intersection treatment, which has been successfully implemented in Michigan, Florida, Maryland, New Jersey, and Louisiana.

Mike on Traffic's Top Site Impact Checklists

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Mike on Traffic provides proven practioners tips to help professionals.

These checklists may be useful:

  • Traffic Data Collection
  • Document Existing Conditions
  • Assumptions to Reviewers
  • Prepare Traffic Forecasts
  • Perform Capacity Analysis
  • Determine Necessary Improvements
  • Determine Whether to Use Simulation
  • Site Review
  • Prepare Documentation
  • Preparing the Proposal
  • Manage the Traffic Study
  • Agency Review