NMDOT to Present Plans for NM 333 and NM 217 Roundabout in Mid-March Meeting

East Mountain area residents will have a chance to learn more about a planned roundabout at the intersection of NM 333 and NM 217 (Mountain Valley Road) when the New Mexico Department of Transportation holds an in-person meeting in mid-March.

No specifics have been announced concerning the meeting’s date and time.

State transportation officials announced plans to transform the high-speed intersection near Interstate 40 into a modern roundabout, citing a history of fatal crashes and persistent traffic delays at the rural junction.

News about the project lit up social media this week with a deep division between whether installing a roundabout is safer than a traffic light.

Despite the varied opinions, the NMDOT’s study concluded that a single-lane roundabout is the most effective solution for the junction, outperforming traditional traffic signals in safety, efficiency, and long-term cost.

The move comes after years of mounting safety concerns. An analysis of crash data between 2018 and 2022 revealed a high rate of injury and fatal accidents at the site, with at least one additional fatality and multiple serious injuries reported since 2022.

Engineers found that the 55-mph speed limit on NM 333 often serves as a baseline rather than a limit, with most drivers traveling 6 to 8 mph above the posted speed. In a high-speed environment, these velocities turn traditional turning movements into high-risk maneuvers. Northbound and southbound traffic on NM 217 currently faces long wait times, which officials say lead to “frustration” and “dangerous turning maneuvers” as drivers attempt to find gaps in the faster moving traffic.

While NMDOT evaluated the installation of a traffic signal, the 2025 analysis determined that a roundabout would provide the “greatest overall benefit”. By physically forcing vehicles to slow to 15–20 mph, the design aims to eliminate the high-velocity “T-bone” and head-on collisions common at rural stop-controlled intersections.

“Both alternatives were found to improve traffic flow and reduce the number of crashes,” the NMDOT report stated. “However, the analysis showed that a roundabout would provide the greatest overall benefit by significantly reducing traffic delays and improving safety”.

The project has already secured critical financial backing. Bernalillo County Commissioner Eric Olivas recently announced that funding has been secured for both the design and construction phases. This includes $220,000 in discretionary funds from Bernalillo County to cover half of the design work, which was matched by NMDOT.  

The project is currently in the “Study and Design” phase. State officials are seeking public input through a survey that remains open until March 14, 2026, with an in-person public meeting scheduled for mid-March. If the current timeline holds, preliminary designs are expected to be developed by Spring 2026, with environmental documentation following later that year.

Improvements Considered and Recommendations

To address these issues, NMDOT conducted an operations analysis of two improvement alternatives:

• • A signalized intersection
  • A single-lane roundabout

Both alternatives were found to improve traffic flow and reduce the number of crashes. However, the analysis showed that a roundabout would provide the greatest overall benefit by significantly reducing traffic delays and improving safety. In addition, a roundabout is more cost-effective to construct and maintain over time.

Economic Lifecycle and Societal Value Analysis

The financial decision between a traffic signal and a roundabout must move beyond initial capital costs to consider the full 25-year service life of the infrastructure.

Capital Construction Costs

The initial cost to build a roundabout can vary significantly based on site conditions. A typical single-lane roundabout might cost between $250,000 and $1.5 million. In contrast, a modern traffic signal installation ranges from $200,000 to $400,000. However, this comparison is often misleading for 55 mph highways. To operate safely at high speeds, a signalized intersection often requires the construction of long, dedicated left and right turn lanes to prevent rear-end collisions. When these turn lanes are factored in, the cost of a signalized project can reach $2 million or more.

Operation and Maintenance (O&M)

The ongoing costs of a traffic signal are substantial. They require constant electricity, periodic retiming of the signal cycles (every 3-5 years), and regular maintenance of the control hardware, detection loops, and signal heads. A typical signal costs approximately $8,000 to $15,000 per year to maintain.

Roundabouts, by comparison, have very low O&M costs. They do not require electricity for signals (only for street lighting), and they have no electronic hardware to fail. While landscaping and snow removal are specialized tasks, the lack of electronic components makes them more reliable and cheaper over time. Furthermore, the service life of a roundabout is approximately 25 years, whereas a traffic signal typically requires a major overhaul or replacement every 10 years.