State Highway 75 corridor study unveiled

A preliminary State Highway 75 corridor study proposes widening the road to five lanes from Timmerman Hill to Saddle Road over the next 20 years.

Design of the future highway remains in question, however, until a number of options—including installation of 15 traffic lights in addition to the existing six—are nailed down.

Cost estimates for the improved highway ranges from $35 to $57 million, depending on the options incorporated in the design. The cost does not include the purchase of additional space necessary for a widened highway.

Officials connected with the project have emphasized they want public input before moving ahead on a transportation plan that could be fraught with controversy.

In a sparsely attended open-house meeting at the Blaine County Courthouse on Tuesday, June 29, a representative from the Boise-based engineering consulting firm CH2M HILL presented the preliminary study. The blueprint proposes dramatic changes to the Wood River Valley’s primary transportation vein.

According to the study, the highway has an acceptable capacity of about 13,000 vehicles per day. Since 1990, traffic has increased 41 percent to a maximum of 15,000 vehicles per day.

According to the study, traffic is expected to increase by another 50 percent over the next twenty years, based on the Wood River Valley’s projected growth.

In a questionnaire distributed at the first public- meeting, respondents emphasized the importance of safe and convenient highway crossings within and between communities.

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According to Betsy Roberts, a CH2M HILL engineer, the study proposes installation of traffic lights every three blocks within the cities of Bellevue, Hailey and Ketchum. A number of traffic lights are also proposed along the corridor between cities.

According to Roberts, the average width of the State Highway 75 is currently 80 to 100 feet, or 33 yards maximum.

Following the widening of the highway to five lanes, the total width will be 90 to 134 feet, depending on the design of medians, shoulders and curb and gutter options. That’s a maximum of nearly 45 yards wide, or a 36 percent increase in width of the highway at its widest point today.

According to Roberts, the Idaho Transportation Department would have to purchase additional rights-of-way over nearly half of the stretch from Timmerman Junction to Saddle Road to accommodate the five lane design of the highway. The cost to purchase these additional rights-of-way is not included in initial construction estimates, Roberts said.

According to the study, speed limits within cities would be increased from 25 to 30 or 35 miles per hour. Fifty-five mile an hour speed limits from Bellevue to Ketchum would be decreased to 45 mph.

The study also shows elimination of the ability for cars to cross the highway at some existing cross streets in Bellevue.

The study says a Highway 75 plan will have to find a balance between the need to move traffic along the corridor versus improving opportunities to cross or enter the traffic stream. Finding that balance will require discussion and finally consensus on an acceptable plan, the study says.

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In answering a questionnaire distributed at the first public-meeting, citizens expressed the need to match highway design to its surroundings. According to the study, a desired element of the corridor plan is to minimize effects on adjacent land, including sensitive areas specifically noted in an environmental review of the construction process.

According to Roberts, CH2M HILL is trying to get public opinion on proposed median options. Roberts said the Idaho Transportation Department would pay for initial median construction, and each valley community would be responsible for maintenance of landscaped medians within it.

Options for the highway design between cities include landscaped, patterned pavement, or standard flush medians.

The landscaped option would provide aesthetic features, but fewer access points and left turn points.

Patterned medians would allow for multiple access and left turn points and would minimize roadway impact on surroundings.

A standard flush median would provide no aesthetic features and no reduction in the perceived width of the highway.

Shoulder design options include painted edge, mountable curb, color variation, color and pattern variation and a reinforced grass shoulder.

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Following the first public open-house meeting, ITD senior transportation planner Bob Humphrey said he was disappointed with the turnout and wanted more public interest in the project.

Measured by the sparse attendance at last Tuesday’s second meeting, there doesn’t seem to have been a discernible increase in locals’ interest even though the meeting was held from 4 p.m. to 8 p.m.

An advisory vote in 1997 showed 85 percent of Blaine County residents wanted improvements to state Highway 75. Humphrey said the corridor study meetings are an opportunity for the public to tell the ITD what improvements it wants.