Engineer discusses Helper interchange design specifications
Helper officials received an update last week regarding the plans for the interchange currently in the construction phase on U.S. Highway 6.
While the project has been in planning stages for several years, construction crews started work on the interchange last week. Representatives of both UDOT and project designer Stanley Consultants attended a city council meeting in Helper on July 6 to update officials on the status of the interchange.
The project bid was awarded to WW Clyde at a total cost of almost $16.3 million.
The contractor will be required to keep one lane open for eastbound and one lane for westbound traffic on U.S. 6. Further, the contractor will be required to keep traffic flowing on North Main across the interchange.
Work will take place during normal construction hours. Though work may begin as early as 7 a.m. and continue as late as 10 p.m., crews will shut down operations overnight.
WW Clyde will be required to give a one week notice to UDOT, Helper officials and residents in the immediate area prior to beginning pile driving.
The interchange has been scaled down dramatically from what it was in the original plans.
Initially the plans called for a four-lane highway through Helper. Current plans allow for a future expansion to four lanes. But construction crews will not expand travel lanes beyond the existing two currently in place.
Construction will begin less than one-quarter of a mile north of the Martin Road crossing and extend south with some portions crossing the pedestrian crossing at Janet Street.
As part of the construction, crews will relocate and replace portions of main water lines owned by Price city and the Price River Water Improvement District. Some portions or other lines owned by Helper will also be relocated.
The contractor has explained to the Utah Department of Transportation that pipe for the relocated lines will be unavailable until September.
As a result, much of the project which was set to take place this summer and fall will be postponed. Construction is expected to be completed in late fall 2007.
The junction of Martin Road and U.S. 6 will be reconfigured to make a safer approach to the highway.
Rather than approach the highway from an angle, Martin Road will connect to the highway at a right angle.
In order to make the connection, the junction of Martin Road will be moved to the north of its current location. The new construction will take place entirely within the current Utah Department of Transportation right-of-way.
Access to Martin Road will be limited, however. Motorists will be able to access Martin Road from westbound U.S. 6. In order to access Martin Road from the highway eastbound, however, drivers will need to turn onto 1100 North or 1000 North.
A deceleration lane will be built for drivers exiting westbound U.S. 6 to Martin Road and an acceleration lane will be built for drivers turning from Martin Road to the highway westbound.
Part of the reason for relocating the junction of Martin Road is to allow safer access for vehicles crossing the highway to North Main, said Bob Jacobs, a representative of Stanley Consultants. Drivers crossing the highway can turn left onto the highway and then right onto North Main. The motorists will be able to take advantage of deceleration lanes as they cross the highway.
From Martin Road, motorists will turn left directly into traffic, but drivers crossing the highway will be able to merge immediately into a deceleration lane and onto North Main.
One of the access issues created by the relocation of the interchange relates to property owned by Margaret and Charles Hamilton on the south end of Martin Road.
Project planners solved the access issue and extended the Helper Parkway along the Price River.
The parkway will be extended north to Martin Road. The north end will serve as driveway access for the Hamilton property.
South of the Hamilton property, the parkway will be for pedestrians only, but will be accessible by service vehicles.
At North Main near Workmen's Market, drivers will be able to turn right onto eastbound U.S. 6 or from eastbound on the highway onto North Main. A deceleration lane will be added for drivers exiting eastbound from the highway. An acceleration lane will be added for drivers turning from North Main onto the highway eastbound.
Drivers will not be permitted to turn left onto U.S. 6 and westbound traffic will not be permitted to turn left onto North Main. Instead, westbound traffic will be required to use the interchange near Swift's.
Near Workmen's Market, plans call for the installation of a road weather information system. The system will be connected into UDOT's road conditions reporting system. Using information collected, transportation officials will be able to better determine when to send plows to the area and monitor the conditions of the highway.
The crossing at North Main near Swift's will be converted to an interchange similar to the interchanges in Price at 100 North and Utah Highway 10. The interchange had been originally planned for a four-lane elevated section of U.S. 6 with two separate two-lane bridges crossing North Main.
The westbound bridge and elevated grades have been eliminated from the plans. However, ramps, bridges and other aspects of the project well be positioned in such a manner that the highway can be expanded to four lanes with minimal demolition and construction.
In order to control noise pollution, 42-inch noise barriers will be constructed on the bridge and portions of the acceleration and deceleration ramps.
Jacobs explained that the barriers will muffle the sound of tires on the highway and will be an improvement over the current level of noise pollution.
The eastbound acceleration ramp from North Main near Workmen's will become an auxiliary lane on the highway, which will then turn into a deceleration lane for the interchange at Swift's.
Likewise, the westbound acceleration lane from the interchange near Swift's will become an auxiliary lane , which will become the deceleration lane for Martin Road.
Using these auxiliary lanes, drivers will be able to drive from North Main near Swift's to Martin Road and not contend with through traffic. Similarly, drivers will be able to drive on the highway from North Main near Workmen's to north Main near Swift's and not merge into or out of through traffic.
The auxiliary lanes will also serve as lanes where drivers can merge into or out of the main travel lanes.
In order to allow space for U.S. 6 to fly over North Main, construction crews will lower North Main by as much as a foot on the west side of the highway. For that to take place, a portion of Garden Street will be reconfigured.
At the interchange near Swift's, drivers will be able to get on or off U.S. 6 and onto either direction of North Main.
The design firm had spoken with the owner of Swift's regarding the size and types of vehicles which supply the gas station with fuel, explained Jacobs. Engineers had taken the turning radius and length of the trucks into consideration in designing the interchange. The designers were confident the trucks would be able to enter and exit the highway safely at the interchange.
One delay in constructing the interchange related to the cost of building four lanes of the highway. Plans for upcoming construction call for the traffic to remain in the existing grade. If U.S. 6 is widened to four lanes, the additional grade will be constructed for westbound traffic and the existing grade will become two eastbound lanes.
In planning for future expansion, the footings, foundation, retention walls and bridge work except the deck will be constructed for all four lanes. Crews will install a deck for two lanes of traffic during the phase of construction. Once the highway is expanded to four lanes, the deck installed will become the eastbound lanes. A second bridge deck will need to be added for westbound traffic once UDOT decides to widen the highway to four lanes.
Acceleration and deceleration lanes for westbound U.S. 6 traffic at the elevated interchange will be positioned in such a way that two additional lanes will fit between the ramps and the travel lanes. Westbound ramps will also be built as closely as possible to the final position required by a four-lane highway. As a result, the westbound exit and entrance ramps will be longer than the eastbound ramps.
Along with the crossing, North Main will be constructed with sidewalks and handicapped-accessible ramps at Garden Street and the U.S. 6 entry and exit ramps. The design will create a third crossing for pedestrians. Currently, there are two pedestrian walkways across the highway. Both walkways are south of the North Main crossing near Swifts.
Jacobs said the pedestrian crossing at Janet Street was set to be replaced in the original plans. But reconstruction of the crossing was cut to reduce the total cost of the project. The crossing would likely be replaced when the two additional lanes are constructed.
One new feature will be a fourth pedestrian crossing at Spring Canyon Wash. Originally, the crossing was designed to be channeled through a two-cell box culvert. However, the box culvert has been redesigned to a three-cell box culvert. Two sections will be constructed 12 feet tall and 12 feet wide. A third section will be 12 feet wide and 10 feet tall, with the floor being elevated two feet above the other two.
The third cell can serve as a pedestrian walkway. The crossing at Spring Canyon Wash will be situated between the elevated interchange at North Main and the reconfigured junction at Martin Road. Pedestrians will be able to access the parkway and travel north to Martin Road or south to North Main.
Councilmember Dean Armstrong expressed concern for the safety of the new pedestrian crossing in the event of a flash flood. The box culvert is designed to allow flash floods to use all three sections. In addition, the helper parkway currently has a bridge across Spring Canyon Wash. The bridge will be replaced with a pair of culverts and a walkway which will be washed out in a flash flood.
Armstrong said he was concerned about the safety of children who may be walking on the parkway. He told Jacobs that there should be some sort of warning system in place to caution pedestrians of the dangers of crossing the wash in a flash flood situation.
Jacobs told Armstrong that he recalled some signs or other warning devices in the plans at the crossing.
In preparation for the project, approximately 30 land owners whose properties are more likely to be impacted by construction have been asked to complete a property inventory prior to construction.
The inventories will be filed and used to determine whether property owners were adversely affected by construction and to what extent.