When to do those relatively early, cheap and minor repairs is determined not only on the roughness index reported to the federal government but also on additional data on pavement cracking, rutting and shifting. Signs of deterioration are also monitored in photographs taken of every 50-foot section of every highway every two years.

With such additional information beyond raw roughness data, the state calculates a "ride quality" index. Under that measurement, which was based on data gathered in 2004, 7 percent of Utah highways are "very good"; 30 percent are "good"; 38 percent are "fair"; 20 percent are "poor"; and 6 percent "very poor."

Braceras said the state has created goals to have 90 percent of its interstate mileage in fair or better condition, along with 70 percent of its other arterial highways and 50 percent of collector highways.

Data for 2004 show it is meeting or exceeding such goals: 90 percent of interstate miles were "fair or better," as were nearly 80 percent of arterials and about 60 percent of collectors.

Braceras said the state's road maintenance approach that the higher the speed the smoother the road, meaning freeways must have fewer imperfections than arterials and collectors that have lower speed limits.

Braceras said that based on current annual surveys of road conditions, UDOT estimates pavement work will cost û180 million a year.

Rough riders, easy riders

Morning News analysis discloses the roughest and smoothest highways in the state. The data are for 2004 and do not reflect repairs made this summer or any recent damage.

For entire lengths of highways, the smoothest overall was U-193 in Clearfield. Its average IRI (what a passenger in the middle of the car would feel) was 39. State officials consider anything between 0 and 42 as "very good" or very smooth on asphalt roads and U-193 manages to average such smoothness for its entire length.

Other entire highways considered the smoothest were U-90 (200 South in Brigham City, with an IRI of 52); U-159 from Garrison to U.S. 6 near the Nevada border (52 ); U-28 from Gunnison to Nephi (54); and U-152 (the Van Winkle Expressway, 55). Note that the state considers ride index numbers between 42 and 65 as "good" on asphalt.

Meanwhile, the single roughest overall highway was U-301 around Steinaker Reservoir. Its ride index was a whopping 180. State officials consider any ride index over 126 to be "very poor" or rough.

Other rough highways included: U-311 around Starvation Lake (IRI of 160); U-144 in Tibble Fork Canyon (IRI of 159); U-296, the road around the American Fork Training School (155); and U-316 to San Juan State Park from U-261 (152).