NM502/Trinity Drive/East Road Upgrade Project

Introduction and background

Planning for improvements to NM502 (Trinity Drive and East Road) began in ~2005. In 2007, a plan (download) was agreed to by Los Alamos County and the New Mexico Department of Transportation. In 2007, the use of a roundabout on Trinity Drive at Central Avenue was considered, but a signalized intersection was chosen as the "preferred option".

In 2010, the County Council, with advice by an ad hoc citizens planning group and the Transportation Board, commissioned MIG, Inc. to perform a redesign study of the NM502 corridor within the County, namely, Trinity Drive and East Road. A long sequence of events has proceeded from this action, described on this website.

Announced to the public in April, 2011, the MIG NM502 Transportation Study's "Final Presentation" dated 4/6/2011 (please see the "Caveat" below re. access to this report) contains a "Preferred Alternative" (p.27) that would reduce Trinity Drive to two through-traffic lanes and install nine roundabouts over the ~4 mile roadway.

Since then, the MIG Study received careful review, and was found to be seriously flawed. The Council decided in September, 2011, to eliminate single-lane roundabouts from consideration and focus current attention on the Knecht to Airport Road section of NM502. A third round of planning has taken place. On February 7, 2012, the Council adopted the latest in a series of "Preferred Options" that will be referred to the NMDOT for further evaluation.

In early 2016, the 95% design was presented. Between the conceptual design and the near-final, detaile design, the planned roundabout has evolved into a different performance class than the original concept. Instead of a single lane roundabout with a slip lane for Eastbound traffic during the evening rush hour, current plans call for a larger, two-lane roundabout. This takes the roundabout from a known-safe-for-vehicles class into a higher speed class with a wide variation among installation-dependent performance problems.

Website contents

Navigation options. The discussion here deals with the issues in great detail. If you're strong and motivated, the "Next" links will take you straight through the thought process. If you'd like the "reader's digest" version, you may click here to go immediately to an application of the background information to evaluation of the Corridor Study. From there, if you wish, links can take you back to various portions of the background material. Finally, if you like to read the last page of a book first, follow this link to see the latest phase of development and the project status. At any page in this section, the "^ Section Start" link will bring you back to this page.

  Priorities for an arterial road  
  Current conditions & performance  
  Traffic basics: congestion, capacity, and utilization  
  Evaluation of NM502 Corridor Plan  
  Citizen response - status  
  Evaluations of the MIG Study  
  County Council action 9/6/2011  
  Reconsidering NM502, from Knecht to Airport  
  County Council action 2/7/2012  
  Project update - 2016  

  • The Los Alamos County Public Works Projects web pages change rapidly, and seem to be occasionally unavailable. Therefore, I have incorporated two Transportation Study files as part of this website, as downloaded on 4/13/2011. The first is apparently a draft file and contains only a few differing items that might be of historical interest (12 MB, 97 pages). The second is a large Adobe Acrobat file (33 MB containing 76 pages) that will download when you click on this link: "NM502PresentationFinal". This second file is the source of the bulk of the information referenced in this discussion under the reference name of "Final Presentation". For those who do not wish to download the large file, I have extracted a few figures and charts and incorporated them into this website.
  • There are some loose ends here: questions that I have asked and have not answered to my own satisfaction.
Acknowledgements. At the outset, I wish to thank the Los Alamos County officials and workers who have provided relevant data and information. I also thank fellow Los Alamosans and friends who have shared their knowledge, experiences, and opinions with me. Special thanks to prime movers in this concerned citizens' effort: Tony Amsden, Howard and Joyce Cady, Norbert Ensslin, Victor Gavron, Joel Williams, and many others for their extensive efforts and for useful information and discussions. I thank the County Council, the Public Works Department, and area drivers for their often-successful efforts in making Los Alamos a good place to live, work and drive.

Latest update: 4/7/16

Contact William Mead
Next >>