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.