Aspen Journalism is compiling a data dashboard highlighting metrics of local public interest, updated weekly on Tuesdays.

September 2022 saw the lowest vehicle counts of the past 20 years due to construction

While the city counted more cars this winter passing through the intersection of Highway 82 and Cemetery Lane than last year, fewer cars went though the intersection this summer.

In January, car counts were 10% up from January 2021 with a daily average of 21,215 vehicles. That’s 6% below the 2000-2020 average for that month.

On average, 22,906 vehicles went through that intersection each day in February 2022. That’s up 11% from February 2021 and and 3.8% above the 20-year average for the month of February.

In March, car counts were 2.8% up from last year with a daily average of 22,394 vehicles passing thought that intersection. That’s down from the historical average of 23,195.

But starting in April, car counts have been lower than last year. In May 2022, as construction crews began a project rebuilding the Highway 82 roundabout and with significant amounts of traffic using a detour on McLain Flats and Power Plant roads, vehicle counts dropped by 17% from May 2021. The city counted an average of 14,355 vehicles passing through the intersection this May, down from 17,313 last year.

In July, typically the busiest month of the year for traffic, and following the completion of the roundabout work, the average daily traffic count of 24,979 was down 7.4% from the 20-year average and 3.3% from last summer.

In September, which saw the most severe traffic impacts with lane restrictions on the Castle Creek highway bridge, the average daily count of 13,875 cars at the Cemetery Lane and Highway 82 intersection was down 39% from September 2021 (and 38% off the 20-year average). That represents the lowest count ever recorded since 1999. This drop doesn’t necessarily mean there were fewer cars in town. However, it’s due to many cars using the Power Plant Road construction detour not being counted.

August data wasn’t available at the time of writing due to fried power cord. The city is currently working on getting the situation sorted out to recover the rest of the August data.

Streamflow down as transbasin diversion resumes

River levels in the upper Roaring Fork basin went down last week, as transbasin diversions to the Front Range resumed.

The Roaring Fork River below Maroon Creek flowed at 139 cfs on Oct. 23, or 103% of average, according to the USGS gauge. That’s down from Oct. 16, when the river was flowing at 150 cfs, and from 107.9% of average.

At Stillwater, located upstream of Aspen, the Fork on Oct. 23 ran at 18.9 cfs or 49.7% of average, down from 38.5 cfs or 93.9% of average on Oct. 16. That put the river below the decreed minimum instream flow for the stretch of 35 cfs. The river’s streamflow dropped from 36.2 cfs on Oct. 18 to 15.9 cfs on Oct. 22.

The Fork’s flow was impacted by the Independence Pass transbasin diversion system that sends Roaring Fork headwaters to Front Range cities. The diversion, which stopped around Oct. 14 but started again on Oct. 19, was sending 20.1 cfs underneath the Continental Divide on Oct. 23 — more water than was flowing down the river at Stillwater.

The Roaring Fork at Emma, below the confluence with the dam-controlled Fryingpan, saw and Oct. 23 streamflow of 366 cfs, or about 106.1% of average. That’s up from 363 cfs, but up from 99.2% of average, on Oct. 16.

Meanwhile, the Crystal River above Avalanche Creek, which is not impacted by dams or transbasin diversions, flowed at 100 cfs, or 109.9% of average, on Oct. 23. Last week, the river ran at 81 cfs, or 81.4% of average.

Air temperature reached 67°F in mid-October

High air temperatures at the Aspen airport reached up to 67°F on Oct. 15, or ten degrees above normal, before going down to 62°F the next day. Meanwhile, low temperatures dropped to 27°F on Oct. 14, before going up to 28°F on Oct. 16. The recent drop in temperatures that occurred this past weekend isn’t reflected in the data yet as Oct. 16 is the latest date for which we have information.

Aspen air remains clean

The air quality in Aspen was “good” last week with an AQI index for ozone ranging from 33 on Oct. 17 to 44 on Oct. 22.

Laurine Lassalle is Aspen Journalism’s data desk editor, where she works to catalogue and analyze local public data. She also heads our our “Tracking the Curve” project, documenting COVID-19 in Pitkin,...