This is an archived article that was published on sltrib.com in 2016, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

Utah highway officials say the riskiest thing that most Utahns do on any given day is ride in a car — and some places are more dangerous to do that than others, based on the number of crashes.

One place drivers should especially put down cellphones and buckle up is northbound Interstate 15 between Draper and downtown Salt Lake City.

It had eight of the state's 10 worst one-mile stretches of freeway for crashes between 2013 and 2015 — with 445 occurring just between 8000 South and 7200 South.

Salt Lake County also is home to seven of the worst 10 segments of nonfreeway state highway sections, with four of them on Redwood Road alone. Main Street in Logan has three.

Salt Lake County also contained all of the worst 10 intersections for crashes on state highways, with two each on Redwood Road, Bangerter Highway and 3500 South.

The Utah Department of Transportation, which maintains data on crashes and roadway characteristics on every foot of 6,000 miles of state-owned roads, provided statistics and analysis at the request of The Salt Lake Tribune. UDOT collects such data, in part, to help identify where safety improvements might be needed. But officials say what really is needed is safer driving.

"We build our facilities to a high standard and most of our roads are inherently safe," said Scott Jones, UDOT safety programs engineer. "What we really can't fix, and what is frustrating to us, is 94 percent of crashes are caused by driver behavior."

For about a year, UDOT has posted an interactive map online of where crashes have occurred in recent years at crashmapping.utah.gov. It is especially designed to help law officers know where they may want to focus their enforcement, but the public may also use it to learn where risk is greatest.

With that data, UDOT compiled for The Tribune top 10 lists for crashes on freeways, other state highways and intersections in the state between 2013 and 2015. (Complete lists are online at sltrib.com.)

Freeways • Northbound I-15 in Salt Lake County has eight of the state's worst 10 freeway stretches of one mile in length for accidents. The other two are in the southbound I-15 lanes in the same area.

The single worst stretch was northbound I-15 between 8000 South and 7200 South, with 445 crashes. Next worse, 9400 South to 8700 South had 424 crashes, followed by 11000 South to 10200 South, with 290.

It shouldn't be surprising that I-15 had so many crashes.

"I-15 in Salt Lake Valley carries more traffic than any other roadway in the state, about 250,000 vehicles a day," Jones said. And northbound lanes toward Salt Lake City are worse "because the morning peak is more concentrated than the afternoon peak, which is more spread out over several hours. So there is more stop and go."

Every day, UDOT sees people weaving across lanes in the worst stretch for crashes as they try to move over for interchanges at 7200 South and I-215.

"The same people drive it every day. They know the recurring congestion happens at the same place, same time, every day," Jones said. "Yet they are distracted enough that there's not attention on what's in front of them — and most crashes are rear-end crashes because of a vehicle stopped."

UDOT is working on a study looking at how to handle burgeoning traffic along I-15 in Salt Lake County. It is different from older studies because it is looking at reducing traffic by better coordinating with the area's mass transit, biking and walking — and even changing land-development patterns to put more people near transit stations or to make neighborhoods more walkable.

It also looks at perhaps shifting more traffic to Bangerter Highway (by converting it more into a freeway) or I-215, and using what officials call "aggressive metering" at on-ramps systemwide to coordinate the entry and spacing of cars to smooth traffic flow.

Nonfreeways • Redwood Road in Salt Lake County had four of the state's worst 10 nonfreeway stretches.

It had 204 crashes between 6400 and 5600 South; 167 between 7300 South and 6400 South; 149 between 4400 South and 3700 South; and 148 between 8000 South and 7300 South.

Jones said UDOT and cities along Redwood Road are performing a study on how to improve safety. He notes that between 5400 South and I-215, Taylorsville consolidated driveways and added landscaped medians to help create a downtown atmosphere and reduce dangerous left turns across traffic.

"A lot of other cities along Redwood Road are looking at similar improvements," said Robert Miles, UDOT director of traffic and safety.

Logan's Main Street has three of the worst 10 stretches for nonfreeway state highways. It had 238 crashes between 1000 North and 1800 North; 200 between 300 North and 1000 North; and 154 between 500 South and 300 North.

"Logan is one of the only urban areas in the country that is not serviced by an interstate highway. So all of the interstate traffic in and out of Cache County has to be serviced by U.S. 91," Main Street, along with all area traffic, Jones said.

UDOT plans to add a new signal at 1600 North on Main Street next summer to replace a stop sign. Crews will also add medians between 1400 North and 1600 North to try to prevent the many accidents from left turns that have occurred there.

In West Valley City, 3500 South had two stretches among the 10 worst in the state. It had 184 crashes between 3600 West and 4400 West, and 162 crashes between Redwood Road and 2700 West.

Jones said 3500 South offers "the only interstate access to West Valley City, and has a tremendously heavy volume" as cars head to I-215 and Valley Fair Mall.

Intersections • The worst intersection on the state highway system is State Street at 4500 South in Murray. It had 166 crashes because of heavy volume there on both roads.

Redwood Road also shows twice up on the list of worst 10 intersections. Its intersection with 3500 South had 125 crashes, while 120 occurred at its intersection with 4100 South.

Bangerter Highway also shows up twice on the list. It had 105 accidents at 9000 South and 104 at 4700 South. Both intersections are soon scheduled to be upgraded to freewaylike interchanges.

Also, 5400/5300 South shows up twice on the list. It had 111 crashes at Commerce Drive near I-15. It also had 106 accidents at 2700 West in a stretch where UDOT recently installed flex lanes that change directions during the day to handle rush-hour congestion.

Evaluation • A high number of crashes does not automatically target an area for UDOT safety upgrades, but it factors into the larger equation. The agency also looks at roadway conditions and traffic volume — and whether a helpful solution can be identified.

"Is there a crash pattern we can identify?" Jones said. "Is there a countermeasure that will reduce those crashes. Where can we effect the most change with the money we have?"

Rural roads, for example, would never show up on a top 10 list for crashes because too few occur at a given spot. But UDOT data showed, for example, many deaths occurring from sleepy drivers drifting off roads and crashing.

UDOT installed rumble strips in 122 miles of highways where data showed such accidents were likely. Safety monitors tracked a drop from 260 crashes in the three years before the rumble strips were placed to 160 in the three years afterward.

Similarly, UDOT found numerous crashes from cars crossing over I-15 medians in rural areas. Installation of cable barriers led to about a 20 percent decrease in such accidents.

High-tech computer modeling also allows UDOT to forecast what expected changes in traffic may do to a highway. For example, U.S. 40 in the Uinta Basin expects an increase in large trucks carrying oil to refineries. Modeling showed wider shoulders as emergency turnouts would be needed — and UDOT is not waiting for crashes to prove the need.

Modeling also predicts how many crashes an individual project may prevent and uses statistics to rank needs statewide. "It is not based on who makes the most emotionally strong argument, but uses data," Miles said.

"This allows us to go beyond where the most crashes are happening, and look at where we can spend those safety dollars to maximum effect."

Miles and Jones agree that the best way to improve safety is beyond their control: getting drivers to pay more attention and follow the rules of the road.

"Please buckle up, drive safely and put away your distractions," Miles pleaded. "Driving really requires your full attention."