I-25/GIBSON RAMP CLOSED: The New Mexico Department of Transportation spent the weekend working on northbound Interstate 25 at the Gibson interchange, according to a news release. This week, the ramp from I-25 southbound to Gibson eastbound will be closed. Crews are scheduled from 9:30 a.m. to 3 p.m. Monday through Friday.
Drivers can expect similar restrictions through Jan. 31, with crews doing bridge maintenance from 9 p.m. to 5 a.m. on weekends and 8:30 a.m. to 3 p.m. weekdays.
NMDOT’s Kimberly Gallegos advises drivers who want to avoid the construction to “take University to Avenida Cesar Chavez as a detour. Variable message boards will be in place, and updates will be made to NMroads.com.”
EASTBOUND RIO BRAVO BRIDGE CLOSING: Jeanne Wyche says via email she takes Rio Bravo to get to work and “since the week before Christmas, the right lane has been closed on Rio Bravo, through the intersection with Isleta. There were no notices that this would happen, and there has been no activity since the lane was closed. This has caused major traffic snafus for those of us who have to go eastbound on Rio Bravo. Can you tell me what is going on?”
Yes – and it will be a few weeks before eastbound Rio Bravo is back to normal.
Gallegos says, “Although it looks like no work has been done at this project site, crews have been underneath the bridge assessing bridge maintenance work that needs to take place.”
She explains in a news release that “a temporary solution was constructed in late December. For safety reasons, only one lane could be used for eastbound travel due to weight-capacity issues. A team of engineers has been working under the bridge, assessing the pier and designing a construction plan to replace the temporary repair.”
She says NMDOT will begin repairing a pier under the bridge starting Jan. 20; work is expected to last three weeks, requiring a complete closure of the eastbound lanes from Isleta Boulevard to Poco Loco Drive.
“NMDOT recognizes the inconvenience the bridge work has caused to the traveling public over the last couple of weeks – especially to those living and commuting in the South Valley,” she says. But “NMDOT’s No. 1 priority is safety.”
A detour will be posted.
HOW ARE THOSE CITY SIGNALS TIMED? Vic Strasburger emails, “It seems like there are many lights timed to change either when no cars are waiting, or on side streets where one car pulls up and immediately can stop 10 cars traveling on a main road. Other than Downtown, it also seems that there are very few areas where the lights are timed to keep traffic flowing.”
Johnny Chandler, public information coordinator for the city’s Department of Municipal Development, says, “Cycle length – the total time needed to serve all movements at an intersection – in Albuquerque ranges from 60 seconds for Downtown signals, 75 seconds for Lead and Coal, 110-120 seconds for most roadways in the city and 130-150 seconds for Coors and Paseo del Norte. Up to 160 seconds for some of the ART signals.
“Most of the city’s signals are what is called semi-actuated. This means that we have detectors, usually magnetic, that determine the presence of a vehicle on lesser-used movements, such as left turns and smaller side streets. When the signal is notified of a waiting vehicle, it will give it a green at its turn in the cycle. If there is not a waiting vehicle, the signal will skip that direction and reallocate the unused green time to the main street.”
As for how signals work together, Chandler says “about 80% of our signals are coordinated. They are generally timed to match the posted speed limit. … We start by determining how much time pedestrians need to cross an intersection, per federal requirements. We then count the number of cars for each movement, either left turn, thru, or right turn, then give each direction the green time need to serve the volume of traffic.
“Once green times are determined and cycle length is picked, each intersection in a corridor is told when to change green using a value called offset. … The intent is for the signal to turn green just as the driver arrives, as it does on Lead and Coal between Washington and University. Factors such as left-turn arrows, two-way traffic and variations in distances between signals can make that a difficult goal to achieve. In those cases, the signal engineer will time the signals to keep stops to a minimum.”
Editorial page editor D’Val Westphal tackles commuter issues for the Metro area on Mondays. Reach her at 823-3858; firstname.lastname@example.org; or 7777 Jefferson NE, Albuquerque, N.M., 87109.