On Sunday, a horrendous traffic 10-car fatal pileup on Interstate 17 revealed just how awful Sedona’s roads are.

Due to cleanup operations and the investigation into the single fatality, Arizona Department of Public Safety troopers completely closed southbound I-17 for five hours and partially closed it for another five.

DPS shunted traffic to alternate routes, including State Route 89A, bringing tens of thousands of drivers headed south on one of the state’s busiest highways through one of the state’s worst bottlenecks.

Canyon traffic was backed up to the bottom of the switchbacks. Drivers reported waiting three hours to make the 13-mile trip that normally takes just over 20 minutes. Even late into the evening when Interstate 17 reopened, cars were backed up halfway up the canyon.

Sedona police did what they could to keep traffic flowing through Sedona by turning traffic lights to flashing yellow and trying to push traffic through Uptown as fast as possible, but even so, the sheer volume of vehicles turned the canyon into a parking lot for almost half a day.

Once vehicles entered the city, they still had to cope with jaywalkers, tourists trying to park, a two-lane State Route 179 and people discovering roundabouts for the first time ever — aka the run-of-the-mill traffic problems that drive Sedona residents nuts on a daily basis.

Such a traffic shutdown is rare — I can’t think of another such incident in the 12 years I have lived in Sedona — but the incident did highlight how terrible our city’s roads are at handling a major influx of cars or serving as an alternate route.

Drivers and emergency crews were beyond lucky that there were no major accidents reported in the canyon during the incident, but a head-on crash caused by a northbound driver could have been nearly impossible to respond to in a timely manner.

Canyon residents, the U.S. Forest Service and drivers are also lucky no carelessly tossed cigarette from a waiting driver kicked off a wildfire in the canyon. Had a blaze started, drivers would have had to abandon their cars as a fire spread and as crews worked to arrive.

If DPS and the Arizona Department of Transportation seriously want to use State Route 89A as an alternate route for Interstate 17 during a major traffic incident, then ADOT should immediately begin funding more road improvements into, out of and through the city.

If not, ADOT should never suggest Sedona as an alternate route; there are simply too many lives at stake should a bad situation on I-17 lead to a catastrophe in Oak Creek Canyon. Instead, build an I-17 frontage road or build connectors to Lake Mary Road.

County and city officials should use the results of the ongoing comprehensive citywide traffic study and this incident to demand more state road improvement funds so that any future detour operation is a logical choice, not a life-threatening disaster we barely manage to avoid through sheer luck.