Road Construction
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The Cone Zone: Week of July 22, 2019

Special Event Traffic Notice: Triathlon Rd Closures Set for this Saturday, July 20
The Los Alamos Triathlons will be starting at 7:00 a.m. tomorrow. Canyon Rd will be closed to through traffic from Central Ave to Diamond Dr from 5:00 a.m. to 1:30 pm.  There will be cyclists traveling on Canyon Rd, Diamond Dr, and West Jemez Rd from 7:00 a.m. to 9:30 a.m. and runners traveling on Canyon Rd and Diamond Dr from 8:00 am to 11:00 a.m. Police officers will be directing traffic at the intersections of Diamond and Canyon, Trinity and Diamond, Diamond and West Jemez Road, and Diamond and Orange Street.
The 26th Annual Los Alamos Kids Triathlon will be held following the Los Alamos Adult Triathlon on Saturday. The event begins at 11:00 am at the Aquatic Center. Canyon Rd will re-open to traffic at 1:30 pm.

Avoid these areas on Saturday morning, slow down and use caution.
Questions? Call the Recreation Division at 662-8170.

Public Works/Traffic Division projects:
Diamond Dr Re-paving Starts Monday, July 22
Star Paving will begin mill and overlay of the roadway surface between Los Alamos Canyon Bridge (aka Omega Bridge) and Sandia Dr/Orange St with an anticipated finish date on or before High School begins August 14. Mill and overlay will then proceed to between Sandia/Orange and the roundabout at San Ildefonso Rd by Sept. 20. Final project completion is set for Sept. 27, weather permitting. Minimal full-depth reconstruction will be needed at some locations along with new striping and markings throughout the project area.
Residents and businesses along Diamond Dr can expect to see and hear activities related to road construction: noise, dust, heavy equipment movements, traffic/commuter impacts and delays, and intermittent parking restrictions.

Four lanes of travel (two in each direction) will be maintained during weekday morning and evening rush hour traffic to accommodate commute times. Two lanes of travel, one in each direction, will be maintained on Diamond Dr during working hours. 

Pedestrian detours will be in place and bike lanes will be closed on Diamond Dr within work zones. Bicyclists and motorists are asked to share the road.

Night and weekend work is anticipated. Crews will be on site Monday through Saturday, 7:00 a.m. to 4:00 p.m. and nightly from 6:00 p.m. to approximately 2:00 a.m.

If time permits, crews may elect to mill and repave the roundabout at San Ildefonso before Aug. 14. This will require the use of flaggers to direct traffic and result in some delays.
ill begin work Monday at Los Alamos Canyon Bridge (aka Omega Bridge) and proceed north to the San Ildefonso roundabout, with a goal to complete work in front of UNM-LA and the High School before school/college resumes for the Fall session August 14. 

On-going Manhole Repairs - Ponderosa Estates in Los Alamos: 
Crews continue adjusting manholes in Ponderosa Estates along Aspen Dr, Sumac Lane and Maple Dr. Work continues through the end of July. The concrete being used is a high strength mix and requires a cure time; therefore, residents are urged to avoid driving over these manholes for the first few days after they are poured. Traffic control will be set up daily in several locations along the project route and residents are urged to use caution when driving through and walking near these work zones. Work hours are 8:00 a.m. to 5:00 p.m. Monday - Friday.

Questions on the above projects? E-mail, or call 662-8150.

Other road construction projects:

East Jemez Rd Closure Tonight & Tomorrow
Starting at 6:00 p.m. tonight, LANL will be closing East Jemez Rd for water line work. The road will be closed until Saturday at 6:00 p.m. The Eco Station will continue to be open, and can be accessed from westbound traffic on truck route.
Questions or concerns about the project can be directed to

NM502 Roundabout and Road Reconstruction (NMDOT project) - Traffic Detour CHANGES on Friday, July 26:
No change to traffic pattern for Monday through Thursday. The contractor continues working on common trench for utilities from 9:00 am to 4:30 pm. Monday - Friday. Expect delays. The speed limit is reduced to 25 mph. NM502 (Trinity Drive) east-bound traffic is being detoured to 4th Street and Central Avenue. After a full stop, motorists should turn right (east) and travel through the construction zone to continue east-bound out of Los Alamos on NM502. West-bound NM502 traffic entering Los Alamos and approaching the roundabout construction zone is being detoured onto Central Avenue; continue west to Knecht Street (or alternatively, continue to the traffic light at 15th Street) then turn left to return to Trinity Drive. There is only one lane of traffic in each direction on Central Avenue. 

On Friday, from 7:00 a.m. to 6:00 p.m., traffic will be detoured as follows to install a major (14") waterline across NM 502 between Central Avenue and Canyon Road: Eastbound traffic will continue on Canyon Rd and back to NM502; Westbound traffic will be detoured onto Canyon Rd at 4th Street and back to NM502. Detour signs will be in place to guide the traffic through the detours. Work should be completed on Friday, barring unforeseen conditions and weather permitting. The two-way traffic from Canyon Road east will stay in the current lane configuration.
Please slow down, use caution and expect delays in this area, especially during peak commute times.
Traffic advisories from NMDOT are available on and motorists are asked to check the site for updates on this project as it proceeds.

TA-21 Clean Up Project - DP Road (N3B project):
No change in truck traffic on DP Rd from last week's report. Clean-up work on the LANL TA-21 Site at the far eastern end of DP Road continues. Large trucks carrying away demolition debris containers will be exiting DP Rd at an average of approximately three trucks per day. Motorists are asked to be alert for trucks exiting; use caution when entering or exiting DP Rd, as this area is near the NM502 Road Reconstruction project.


About this page... This page provides citizens with basic information on County and non-County road construction projects. We are maintaining the page in the interest of keeping our citizens, visitors and commuters informed as a public service with one landing page where all information or links to information can be found.

About the Cone Zone...
The weekly Cone Zone report is posted here at the top of the page on Friday afternoons from March 8 through November 15, 2019, and then again from March through November 2020, in order to support public outreach especially for the NM502 Roundabout project, which is being constructed by the State of New Mexico's Department of Transportation over two construction seasons in Los Alamos. 

More about the State of NM DOT's NM502 Reconstruction & Roundabout Project...

Here is a project map showing projects in the area of NM502 and the roundabout/near DP Road which may cause additional traffic congestion heading into the busy summer months. Motorists are asked to use caution in this area. Staging for the equipment and infrastructure needed for the NM502 project (a fenced, secure area for Star Paving) is located on DP Road, as shown on this map.

Here is a project drawing showing what the NM502 Roundabout will look like when completed (furnished to the County by the State of NM DOT)

Due to utilities conflicts along NM502 for the new roundabout to be constructed, new storm sewer, retaining walls and grade changes associated with the new road design, infrastructure for water, sewer, electric, natural gas and fiber optics will be replaced and relocated as follows:

• Replace and relocate 2000 feet of water transmission line
• Replace and relocate 4500 feet of water distribution lines, including all service connections and fire hydrants in the corridor
• Replace and relocate 4000 feet of natural gas lines including all services lines in the corridor
• Replace and relocate 350 feet of sewer lines
• Replace and relocate 5000 feet of underground electric lines, including duct banks, conductors, transformers, vaults and all service connections in the corridor
• Replace and relocate 1400 feet of the fiber optic systems owned by Los alamos County and Comcast

Here is a link to the NMDOT webpage for all District 5 Proposed and Active Projects with additional information from the State. Scroll past all Proposed projects to the bottom of the page where you will see NM502 listed as an Active project. The State has posted additional information about roundabouts on this page, along with the March 20, 2019 public meeting presentation. The presentation shows many aspects and views of the construction project and detours that can be anticipated as it proceeds over the next two years. 

Nearby projects:
N3B - TA-21 Clean Up
N3B and their contractor will be working this year and next year on an environmental remediation/clean up project at the former TA-21 site (far eastern edge of DP Rd).

Here is a Fact Sheet about that N3B project which involves hauling away non-radioactive or low-level waste after properly packaging it in containers.

Infrastructure for Bethel Housing Developments - installation on or along DP Road:
Bethel Development's “Canyon Walk” apartments will be starting infrastructure and construction of new affordable workforce housing, scheduled to begin August 2019 with completion by August 2020. A second housing project by Bethel called “The Bluffs” on DP Road is also being considered and work could begin for additional Senior Housing. Both of these sites are referenced in the main NM502 project map shown above.

Future DP Road Infrastructure (long-term County project)
The County could begin installing infrastructure for the DP Road area in the future, as more land parcels become available and after TA-21 remediation is completed. These parcels are part of DOE Land Transfers that could be used for future light industrial or residential development. The infrastructure would extend to the TA-21 site as a "spine" for future development on the north and south side of the road. DP Road needs to be upgraded to include basic infrastructure that could be used by existing or new businesses or homes. For example, there is currently no sewer line in this area. The County applied for grant funding last year for offsetting these types of infrastructure costs for the DP Road project, but it was not approved.

What else do I need to know?

For general questions about construction, you may call the Customer Care Center at 505-662-8333 and a representative will direct your call to the appropriate office. 

For feedback on this webpage, send an e-mail to the webpage administrator.

What's next? A note about planned or possible future road projects:

Below is a listing of projects that motorists WILL or MIGHT see occurring in Los Alamos that might further impact NM502/Trinity Drive:

Diamond Drive (updated status on June 28, 2019):

Reconstruction of the road from Trinity Drive to the San Ildefonso roundabout by the Golf Course is set to occur in July. In March, the County applied for and received emergency funds for road reconstruction after several harsh winter snow events in December and January severely damaged Diamond Drive. Work is set to be completed near the high school before school gets underway mid-August. 

Canyon Rim Trail Underpass:

An underpass to connect LA Mesa trail underneath NM502 and south to the Canyon Rim Trailhead is wrapping up design stage and set to go to construction Spring 2020. It is located further east from the NM502 project. 

Work in Los Alamos on various projects by the County or by others may get underway in 2019 or 2020 that might cause some traffic slow-downs:

Trinity Drive:
In June, the State DOT announced that they have secured funding to do much-needed roadway, curb and gutter repairs on Trinity Drive, from Diamond to the eastern edge of Los Alamos. Work could get underway as soon as July or August. A portion of the work would involve a "road diet" near the turn off to the former LASO building site (now expected to become The Hill apartments with construction beginning soon.)

There could be several projects occurring over the next two years while NM502 is under construction at the eastern edge of Los Alamos:

Construction on new businesses/buildings at the 20th Street lot 

Traffic light installation at 20th and Trinity Drive once new businesses are constructed.

New business construction along Trinity Drive (Natural Grocer is expected to build a store at the Shriner's Club lot)

SR4/Truck Route intersection:
This has been a high-profile project for several years - there are design plans in progress but no funding set aside for construction. At this time, and because of the impact that will already occur for increased traffic on SR4/Truck Route during the NM502 project for two years, it is not anticipated that there would be road work on the intersection at the same time.

Watch for updates on this page for Future Projects such as the ones listed above, or, for new projects to be added as they are identified. As the County gets more details, updates will be posted here.

Construction can be difficult and present special challenges for businesses caught in the construction zones and related/adjacent areas. Motorists tend to avoid orange barrel zones and this can have significant economic impacts on businesses. Los Alamos has many small, locally-owned and operated restaurants, specialty shops and stores on the eastern edge of Los Alamos. The County encourages residents and visitors to support local businesses, especially those on DP Road, which will likely be impacted by the construction. Other businesses at Entrada Business Park, East Gate, along Trinity/Knecht (Mari Mac and Smith's Marketplace and further west on Trinity) as well as those on Central Avenue may likely be impacted, too. The County is working with MainStreet and the Chamber of Commerce to find ways to mitigate impacts and support them, but your help is urgently needed! Allow extra time for patronizing these businesses, but please don't shy away just because of construction! They need your help to continue to operate all of your favorite and valued restaurants, shops and other small businesses to be able to provide you great products and services.