What to do with NM502?

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I submitted the following Letter to the Editor of the "Los Alamos Monitor" that summarizes the NM502 decision making from 2007 to the present, and includes some recommendations. The Letter appeared in the February 7, 2012 edtion.

Planning for the future of NM502 or parts of it has been underway since before 2007, when NMDOT and the County agreed on improvements to the Knecht to Airport Road section of NM502 that would add an eastbound lane. As a result, $4M from the State and about $1.2M from the County are currently sketched into budgets for the project in 2014.

In 2010, a $300K contract was awarded to MIG, Inc. and the “NM502 Transportation Corridor Study” final report, delivered in June and finalized in September of 2011, put forward a $40M plan that would reduce Trinity from five to three lanes total (from four to two through-traffic lanes) and install nine (9) single-lane roundabouts.

Joyce Cady and Victor Gavron obtained 500+ cosigners on a petition favoring four “through” lanes on Trinity. We looked at the proposed roadway, studied the highway and traffic literature and current conditions, and concluded that it could not carry current traffic volumes. Further, we found claims that “Trinity is dangerous” were based on mistaken analysis. Eventually, Ourston Roundabout Engineering confirmed that single-lane roundabouts could not carry even today’s traffic load. In September, 2011, the Council ruled out single-lane roundabouts.

Now, five months later, the “Zimmerman Option” has been brought forward, a plan that would keep the Knecht to Airport segment of NM502 at two through lanes and install a roundabout at the intersection of Central and Trinity. This option applies traffic calming and includes four choke points: two lanes of eastbound traffic must merge into a single lane (near Canyon), a roundabout entrance where 2-to-1 merging of eastbound traffic on Trinity would often be necessary, and two speed-control objects at Tewa and Airport that would affect traffic in both directions.

Our observations and calculations, and the professional opinions of NMDOT and Parsons-Brinckerhoff (PB), indicate that one through-traffic lane in each direction is inadequate for existing traffic. PB has put two options on the table: (1) a “5-lane” (4 thru lanes) option and (2) a “4-lane” option (2 EB and 1 WB thru lanes, as in the 2007 plan). Both of the PB options include a traffic signal at Central and Trinity.

Recently, NMDOT stated in writing that they would support the PB “5-lane” or “4-lane” options (with two through-traffic lanes in each direction). NMDOT would consider other options if negotiations to transfer NM502 to County operation were undertaken.

The safety and comfort issue is complex, but the crux of the argument, as I see it, is that NM502 has a very good safety record, while roundabouts are widely acknowledged to be poor in safety for bicycles and motorcycles. The data on pedestrian safety is mixed, but the situation for pedestrians at a two-lane roundabout is recognized as “challenging” for children, the elderly, and handicapped users (NCHRP 672).

There is a fundamental difference in values at work: one group thinks constraining motor vehicle traffic on NM502 will help the residents who live near it and improve the suitability of Trinity for business. The other group (including myself) thinks motor vehicle movement along the NM502 artery is vital to Los Alamos, that four through-traffic lanes are needed, and that the Zimmerman Option will increase congestion and, if implemented, would not be good for local residents, businesses, or Los Alamos as a whole. This dichotomy arises out of history and growth of the County, and worsens through the County’s planning and zoning policies, which have led to growing residential areas next to a major arterial road.

For the Knecht to Airport segment of NM502, increasing the number of lanes would provide better, more reliable traffic flow. This segment of NM502 is congested now during more than two hours of the day. The PB 5-lane plan would bring this section up to modern motor vehicle transportation standards, including reserve capacity to allow for growth, changes in traffic patterns, non-optimal driving conditions, and emergencies. If the 5-lane option is not feasible, the 4-lane option would at least be a step in the right direction.

Staying with two through-traffic lanes and adding “traffic calming” features, as in the Zimmerman Option, would clearly reduce the roadway capacity and reliability while increasing congestion. It would also mean that the County would have to take on all the expenses associated with NM502. I believe this is the wrong direction for the future.

I see Central and Trinity as representative of the two sides of this design debate. Central is the result of using traffic calming to hold down vehicle speeds and create a safe (but congested) environment, while Trinity offers greater efficiency and freedom of motor vehicle travel, controlled by signals, speed limit, and enforcement to maintain safety. When it comes to safety records, the two streets are comparable, though comparisons are difficult because Trinity carries more cars, while Central has more pedestrians. In terms of reliability, comfort, and emergency services that depend on motor vehicle transport, I think Trinity clearly outshines Central.

The Council is faced with a decision where both goals and “facts” are in contention. I hope they will reach a wise decision.

William C. Mead

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