TRAX air quality study expands

This article, originally published in @theu, February 26, 2020, was written by Paul Gabrielsen, Science Writer, University of Utah Communications

For more than five years, University of Utah air quality sensors have hitched rides on TRAX light rail trains, scanning air pollution along the train’s Red and Green Lines. Now the study, once a passion project of U researchers, has become a state-funded long-term observatory, with an additional sensor on the Blue Line into Sandy and Draper and additional insights into the events that impact the Salt Lake Valley’s air, including summer fireworks and winter inversions.

In a new study published in Urban Science, researchers including Daniel Mendoza and Logan Mitchell report the latest from the TRAX Observation Project, including data validation studies that bolster the data’s value for other researchers and three case studies from recent events showcasing the abilities of the mobile air quality sensors.

What’s new: Blue Line and data validation

UTA’s TRAX system consists of three light rail lines: red, green and blue. Up until November 2019, U sensors measuring ozone and particulate matter were installed only on the Red and Green Line trains, because both lines used the same train cars. These two lines travel through downtown Salt Lake City, the central I-15 corridor and the valley’s west side. With an additional sensor on the Blue Line, however, air quality measurements now extend into the Salt Lake Valley’s southeastern quadrant.

“That’s a really important area of the valley,” Mitchell says. “There’s a lot of people down there.” The Blue Line also goes up and down in elevation, just as the Red Line does as it ascends from downtown Salt Lake City to the U campus. “Since elevation is such a key part of the air quality and understanding the depth of the inversion on different days, under different conditions,” he says, “it’s going to be a really important piece of the dataset for us.”

Extending into the south valley also allows researchers to learn more about how air masses move back and forth between Salt Lake and Utah counties, through the narrow Point of the Mountain passage.

“That’s actually really critical because we sometimes have very different meteorological phenomenon going on between the two valleys,” Mendoza says. “We can now examine in our basin an exchange of air masses.”

The other major development in the TRAX Observation Project is the validation of the data coming from the mobile sensors. This is an important step in a pioneering project such as this, and serves along with quality assurance and quality control protocols as a certificate on the archived data now being made available to other researchers. It also assuages any concerns that the air turbulence caused by the moving train might skew the readings.

The experiment involved a stationary particulate matter sensor placed about 10 feet (3 m) from the rail line that would take readings whenever the TRAX trains were within 500 feet (150 m) of the sensors. Comparing the mobile and stationary readings, Mendoza says, showed 96% accuracy. “That really gives us a great deal of confidence that our TRAX sensors are actually performing really well compared to regulatory sensors and can be used for health studies, policy and so on,” Mendoza says.

Watching the fireworks

With five years of continued observations, the TRAX Observation Project has captured many air quality events. Mendoza, Mitchell and their colleagues document three particular events in their paper: an elevated ozone event from August 2019, a cold air pool inversion event in November 2019 and the fireworks on July 4, 2019.

The fireworks event was unique—it wasn’t a phenomenon caused by an atmospheric event or by the geography of the Salt Lake Valley. It was an incidence of multiple point sources of particulate matter air pollution, allowing observation of how those plumes of particulate matter moved through the valley.

Following generally good air quality, hotspots of elevated pollution started appearing in the TRAX data between 10-11 p.m. on Independence Day. By midnight, the majority of the valley was experiencing moderate to unhealthy air quality.

Mendoza says that the train data shows not only the dispersion of the smoke—something you don’t see in wintertime inversions, which have low atmospheric energy—but also the evening winds coming down Emigration Canyon on the valley’s east side, which washes out some of the air pollution.

“These are examples of the kinds of things that we’re seeing that you couldn’t see with stationary monitors,” Mitchell adds. “It’s helping us understand where the gradients are in the valley, how they evolve through pollution events such as during the Fourth of July or an inversion or an ozone event. You can see the air masses moving around. You can see where the pollution is and how it moves from different parts of the valley.”

Next steps

Next, Mitchell says, the team hopes to add sensors that measure oxides of nitrogen and carbon monoxide, both important components of atmospheric chemistry. They’d also like to expand the study to light rail trains in cities such as Portland or Denver.

“It would be really interesting for us to be able to compare the spatial patterns we’re seeing here with another city that has different topography around it and a different mix of emission sources,” Mitchell says, “so that we can understand how cities, in general, are being affected by these things and how that’s similar or different from what’s going on in Salt Lake City.”

Find the full study here.

Media Contacts

Logan Mitchell | research assistant professor, Department of Atmospheric Sciences

Daniel Mendoza | research assistant professor, Department of Atmospheric Sciences; pulmonary fellow, Division of Pulmonary Medicine, School of Medicine
Office: 801-585-6861 | Mobile: 801-505-8253 | 

Paul Gabrielsen | research/science communications specialist, University of Utah Communications
Office: 801-585-6861 | Mobile: 801-505-8253 | 

UTA on Demand by Via

This article, originally published in @theu, February 11, 2020, was written by Claudia TrochezCommuter Services

Thanks to UTA’s Ed-Pass, students, faculty and staff can ride the bus, TRAX and FrontRunner for no additional fee, making public transit the obvious choice for commuting to campus. Depending on where you live exactly, UTA service can either be an invaluable resource or a not-so-convenient option that doesn’t work well with your schedule.

For residents in southern Salt Lake County where UTA service is less abundant, accessing public transit is more challenging. To help bridge the gap, UTA launched its microtransit pilot program, UTA on Demand by Viawhich intends to enhance connectivity to TRAX and FrontRunner lines for commuters in the southern part of the valley by providing on demand rides to and from TRAX stations.

What is UTA on Demand by Via? 

UTA’s microtransit pilot program serves about 65 square miles in southern Salt Lake County, serving the cities of Bluffdale, Draper, Herriman, Riverton and South Jordan. The service area includes seven TRAX and FrontRunner stations with designated pickup and drop off locations, making connections to campus more accessible than ever.

Via’s technology matches multiple riders headed in a similar direction into a single van, with quick and efficient routing, avoiding lengthy detours. After requesting a ride, the app will display the pickup location where the vehicle will meet you. Via is a corner-to-corner service, meaning riders will be picked up and dropped off close to their destination.

How does it work? 

Riders may hail a van by using the Via app, available on the App Store and Google Play. The microtransit service operates Monday through Friday from 6 a.m. to 9 p.m. and is available to students, faculty and staff at no additional fee. University affiliates with a valid uNID should use their Ed-Pass, in lieu of paying fare, by hitting the ‘UTA Pass/Ticket/Transfer’ when signing up.

ADA riders may request an accessible van by selecting ‘wheelchair accessibility’ in their profile.

For example, if you live in Draper and work on campus, you can get a lift to the Draper Town Center or Kimball Lane TRAX stations by requesting a UTA on Demand ride through the Via app. At the end of the day, you can be picked up at the TRAX station and return to where you started near your home, the grocery store or anywhere within the service area (see map below) for no charge. The service will also be useful for patients traveling to and from the South Jordan Health Center.

Why should I ride UTA? 

A perk of the U community, all current students, faculty and staff members may ride UTA services, including the microtransit program, without paying fare. Choosing UTA over driving allows you to save money on car-related expenses including gas, maintenance and parking permits.

In addition to saving some green, you can also be green by choosing UTA over driving. Salt Lake City’s poor air quality is undeniable during inversion season. According to a recent study, “at least 85% of harmful emissions come from fossil fuel,” meaning the CO2 produced by cars is the lead contributor to the air quality problem Utahans face. Riding UTA will continually help reduce emissions and help keep our air clean.

Driving to the university campus from southern Salt Lake County may take anywhere from 30 to 80 minutes or more, depending on traffic and weather. While riding UTA will not likely decrease your commute time, it will certainly ease its difficulties and be safer, too. You’ll be able to start your workday sooner, catch up on emails, read or watch Netflix, instead of sitting behind the wheel in traffic or on icy, dangerous roads.

Share your thoughts

UTA on Demand by Via is a pilot program and UTA wants to hear from you. Take this survey to share your thoughts and help UTA study effective ‘first-and-last mile’ connections to our bus and rail services.

For more information on UTA on Demand by Via and all other services, visit call 801-RIDE-UTA.

Slow Your Commute

How shifting your commute can add to the journey (and clear our air)

By Kate Whitbeck, Communications, Sustainability Office

We have all heard of slow food and fast fashion, and how we want to seek out the first and avoid the second. What about slow transportation? It’s a concept that suggests getting to your destination as quickly as possible shouldn’t be your primary goal. Your commute can serve many different purposes. Slowing your commute can add to the journey (and clear our air).

Before I started working at the university, I was a slave to my vehicle, racing off each morning to drop my kids at school then driving 25 minutes to my office—which was in a public transit desert—and then racing back to pick up my kids, fitting in a few errands and driving home. I arrived home stressed from dealing with traffic, frustrated that I hadn’t fit in any exercise and anxious that I hadn’t had time to finish my work at the office.

When I started working at the university I had the great fortune to became a regular public transit user. There were a number of factors that made it work: 1) I live within a few miles of the campus; 2) There are at least three bus routes that travel to the U within about 4-5 blocks of my house; and 3) All my children could get to school using the same bus route. It didn’t hurt that my university ID also covered my fare.

Admittedly, for me it does take longer to get from place to place using public transportation. At first, I struggled thinking that this was wasted time that I could spend doing other things until I realized that my commute brought me home at the end of the day without the frustrations of dealing with traffic and had allowed me to fit in my 10,000 steps, connect with my children in a relaxed way and saved me money. This is when I shifted my attitude around my commute and embraced slow transportation.

Slow transportation is about rejecting speed as the objective and reimagining our transition from one place to another as an opportunity to check off other boxes.  Your morning commute (in something other than a single-occupant vehicle) can serve as the following:

Exercise Time: Depending on what your commute looks like it can take the place of a trip to the gym.  The bus route that runs to the U most frequently is further from my house. It also drops me further from my office. This could be viewed either as an impediment or as an opportunity to get in more steps.  Biking or walking to work serve that same purpose.

Work Time: Taking the train and the bus can allow you to put in extra work time. An uninterrupted hour at the beginning and end of the day can allow you to use your time in the office more effectively.

Relaxation Time: Taking TRAX, FrontRunner or the bus allows you to listen to your favorite podcast, catch up on the news, or scroll through social media. If you own a good set of noise-canceling headphones you can turn your transit commute into a meditation session. Doing absolutely nothing but staring out the window and letting your mind wander can also feel incredibly liberating. You arrive feeling refreshed and ready to get to work.

Connection Time: In my case, my commute allows me another 15 minutes of uninterrupted, undistracted time with my children. I am not fighting traffic, thinking about where to park, or battling unsafe road conditions. I get that not everyone’s lives allow for this intersection, but it can allow for connection of a different sort.

Slowing down your commute, especially by walking or biking, allows you to connect to your city and its inhabitants in a new way. When you walk the last few blocks to your destination you notice things that you wouldn’t see when whizzing by in a car. You notice the new businesses that have opened, those that have shut down. You notice that the neighbor two blocks away painted their house blue. You begin to recognize other slow commuters. You interact with strangers giving directions or chatting at the bus stop. These interactions help us feel grounded and connected to our community.

Sometimes I think we weren’t meant to move so quickly from one place to the next. When we are dependent on our own two feet to get places, we are far from the fastest species on the planet. For the majority of the millennia our species has inhabited this planet it took time to get from one place to another, enough time to mentally transition so that when we arrived at our destination we were present in a different way. Maybe we haven’t yet evolved to travel so quickly from one place to another.  Maybe we all need to try a little slow transportation.

 

Throughout February, consider slowing your commute. Take action on air quality by tracking your commute behaviors with the Clear the Air Challenge, a statewide competition that aims to reduce emissions from vehicles by promoting alternative transit options. Join the U team at travelwisetracker.com/s/university-of-utah.

Mark your calendar for Winter Bike to Work Day – February 13th, 4-6 pm. Cyclists are invited to stop by our two pop-up locations on Guardsman Way and the Legacy Bridge for hot drinks and free resources on their commute home.

Does public transit reduce pollution?

This article, originally published September 6, 2019 in @theu, was written by Paul Gabrielsen, science writer, University of Utah Communications.

Public transit has long been an answer for people looking to leave their car at home and reduce their air pollution emissions. But now, with better rider tracking tools, the University of Utah and the Utah Transit Authority can better answer the question: How much does public transit reduce pollution emissions?

In a paper published in Environmental Research Communications, University of Utah researchers Daniel Mendoza, Martin Buchert and John Lin used tap-on tap-off rider data to quantify the emissions saved by buses and commuter rail lines, and also project how much additional emissions could be saved by upgrading the bus and rail fleet. The study was conducted in cooperation with the Utah Transit Authority and the Utah Department of Environmental Quality, Division of Air Quality.

High-resolution rider data

Mendoza and his colleagues are certainly not the first to ask how much pollution public transit can save. But a couple of recent technological advances have enabled them to answer the question with a level of detail previously unparalleled.

The first is the advance of tap-on tap-off farecards that provide anonymized data on where those riders who have electronic passes enter and exit public transit. Approximately half of UTA’s passengers use an electronic fare medium. “Now we can truly quantify trips in both time and space,” Mendoza says. “We accounted for all of the 2016 passenger miles by scaling the farecard data, and we know which trips farecard holders make on buses, light rail and commuter rail.”

The second is the General Transit Feed Specification system. It’s the data source that supplies Google Maps with transit information to help users find the bus or train they need. With that data source, the researchers could track where and how often UTA’s buses and trains run.

So, with high-resolution data on the movement of both vehicles and passengers, the researchers could paint a nearly comprehensive picture of public transit along the Wasatch Front.

Balancing emissions

So, with that data, the researchers could quantify the emissions produced and miles traveled of the transit systems (TRAX light rail uses electricity produced outside the Wasatch Front, hence the emissions aren’t in Salt Lake’s air) and balance that with the miles traveled by passengers and the estimated amount of car travel avoided by riding transit.

On weekdays during rush hours, and in densely populated areas, the balance was clearly on the side of reduced emissions. “That tapers off significantly during the evening hours, on the outskirts of the city, and definitely during the weekends,” Mendoza says. In those situations, the number of passengers and how far they rode transit did not offset certain criteria pollutant emissions. (Criteria pollutants are six common air pollutants that the EPA sets standards for through the Clean Air Act.)

For transit to improve its regional reduction in emissions, particularly PM2.5 and NOx, the following strategies, alone or in combination, could be employed: more daily riders per trip, more clean-fuel buses and train cars and/or fewer low-ridership trips.

What-ifs

The current study looks at the bus and train fleet as they are now, with some UTA buses around 20 years old and FrontRunner trains whose engines are rated a Tier 0+ on a 0-4 scale of how clean a locomotive’s emissions are (Tier 4 is the cleanest; UTA is scheduled to receive funds programmed through the Metropolitan Planning Organizations to upgrade FrontRunner locomotives to Tier 2+). So, Mendoza and his colleagues envisioned the future.

“What if we upgrade all these buses, some of them from 1996 or so?” Mendoza says. “They emit a significantly larger amount than the newer buses, which are 2013 and newer.”

What if, they asked, UTA upgraded their buses to only 2010 models and newer, fueled by either natural gas or clean diesel? And what if the FrontRunner engines were upgraded to Tier 3?

Emissions of some pollutants would drop by 50%, and some by up to 75%, they found.

“Now, with this information, UTA can go to stakeholders and funding agencies and say, ‘Look, we’ve done this analysis,” Mendoza says. “This is how much less we can pollute.’”

Mendoza adds that taking transit offers additional benefits besides reducing air pollution. Taking transit gives riders time to read, work or listen while traveling. How does Mendoza know? He’s a dedicated transit rider. “I always get to where I need to go pretty much on time and completely unstressed,” he says. “I almost never drive.”

Find the full study here.