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I-84, Franklin Road to Karcher Interchange

The Idaho Transportation Department is constructing improvements to Interstate 84 between Franklin Road (Exit 29) in Caldwell and Karcher Road (Exit 33) in Nampa.

The work is expected to improve mobility, increase safety and benefit the regional economy for many years.

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Para más información y para recibir una hoja de inforamación, por favor llame 208-334-8567
Construction Update

Variable Speed Limit Signs

ITD is using variable speed limits within the Interstate 84 construction zone in Canyon County in order to improve mobility and preserve safety throughout the project’s lifespan.

The variable speed limits will allow for responsive adjustment to speed as activities within the work zone allow. When construction crews are not in the work zone or when safety barricades are in place, the speed limits can be raised from 55 mph to 65 mph. This further promotes mobility without sacrificing safety on the Interstate.

A flashing beacon will notify drivers in advance when speed limits are reduced from 65 mph.

Linden Street Underpass CLOSED

As part of the project to improve I-84 between Caldwell and Nampa, the Idaho Transportation Department is replacing the Linden Street interstate bridge. Construction has required the Linden Street underpass to closed. The closure began in July 2021 and a detour is in place.

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Traffic Impacts

Construction is underway on I-84 between Franklin Road (Exit 29) in Caldwell and Karcher Road (Exit 33) in Nampa. ITD will add a third lane in both directions and replace 20 bridges and other structures.

What’s happening now:

  • Traffic has shifted to temporary  outside lanes on I-84.
  • Crews are working in the median and shoulders are restricted.
  • Speed limit is reduced to 55 mph while crews are working near traffic.
  • Closures will be scheduled on interchange ramps.
  • One lane of eastbound or westbound I-84 may be closed at night.
    • Eastbound I-84: 10 p.m. to 5 a.m. M-F 10 p.m. – 7 a.m. Sat/Sun
    • Westbound I-84:10 p.m. to 6 a.m. M-F 10 p.m. – 7 a.m. Sat/Sun
  • Construction may be noisy at night due to back up alarms and vibrations from equipment.
  • Construction work may cause dust and debris.

Please drive carefully.

Project Overview

This project is necessary to improve safety and mobility on I-84 in Canyon County. The existing interstate can no longer accommodate current traffic volumes at peak periods of the day. As the Treasure Valley continues to grow, congestion in this corridor will increase.

Improvements include:

  • Widening I-84 to three lanes in each direction from the Franklin Road Interchange in Caldwell to the Karcher Road Interchange in Nampa.
  • Replacement and widening of canal, culvert and lateral crossings.
  • Replacement of the Middleton and Ustick overpasses.
  • New noise walls along I-84 near Ustick Overpass and on the Franklin westbound on-ramp.
  • Replacement of the I-84 bridges over Linden Road.
  • Adding an additional lane on Franklin and Karcher westbound off-ramps.
Early Summer 2021
Construction begins.
Late Summer 2021
Traffic shifts to outside lanes and crews begin working median.
Summer 2022
Traffic shifts to median and crews will begin rebuilding outside lanes.
Summer 2023
All work expected to be complete
Frequently Asked Questions
You've got questions, we've got answers! Here are some of the most common questions we've received about this project.
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General
Linden Street
Variable Speed Limits
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General
Why isn’t ITD adding a new interchange to I-84 between Karcher/Midland Boulevard in Nampa and Franklin Boulevard in Caldwell?
Why isn’t ITD adding a new interchange to I-84 between Karcher/Midland Boulevard in Nampa and Franklin Boulevard in Caldwell?

ITD conducted a detailed traffic analysis of I-84 in 2018. ITD analyzed whether or not a new interchange would be needed along I-84 between Nampa and Caldwell. The analysis concluded widening I-84 and improving interchanges at Karcher/Midland (in Nampa) and Franklin Road (in Caldwell) will serve the needs of traffic beyond the design year 2045.

Linden Street
Why is ITD closing the Linden and Ustick overpasses at the same time?
Why is ITD closing the Linden and Ustick overpasses at the same time?

ITD made the difficult decision to close both Linden and Ustick this year in order to keep the I-84 project on schedule. This section of I-84 includes 20 bridges and other structures (canal crossings, culverts, etc.) that must be reconstructed to accommodate a third interstate lane. Many of these must be reconstructed at the same time.

In the case of the Linden underpass, the work zone is too tight to safely accommodate daily traffic volumes. However, emergency access will be available for police, fire and paramedics. Later in the project, ITD plans to open Linden Street to local traffic during the day. We regret the inconvenience to local travelers and look forward to the project completion. We appreciate your patience.

General
Why isn’t I-84 in Caldwell getting widened to four lanes instead of three?
Why isn’t I-84 in Caldwell getting widened to four lanes instead of three?

ITD’s detailed traffic analysis determined that three lanes on I-84 have shown to adequately serve the traffic needs in this area until 2045.

Once there is a need to expand, further widening will be possible. The current planned improvements will be built with space on either side of I-84 in Caldwell to add a fourth lane when necessary.

General
Will there be any crossovers for emergency service providers?
Will there be any crossovers for emergency service providers?

Yes, two emergency crossovers will be included in the I-84 Caldwell to Nampa project. Additional crossovers are not possible due to significant grade differences between the eastbound and westbound lanes of I-84.

General
How long will construction take?
How long will construction take?

Work between Karcher/Midland Boulevard and Franklin Road (Exit 29) in Caldwell began in Summer 2021 and is expected to be complete by summer 2023.

General
Can construction happen 24/7 to complete the project sooner?
Can construction happen 24/7 to complete the project sooner?

Crews cannot work 24 hour shifts due to lack of availability, as well as the significant cost for overtime. In addition, around-the-clock construction would create additional noise near residential areas of the project.

General
How do I learn more about the project?
How do I learn more about the project?

To learn more:

Visit the project website at ITDPROJECTS.ORG/84CORRIDOR

Text 84Corridor to 1-866-ITD-84CC

Call 208-334-8002

Email 84CORRIDOR@ITD.IDAHO.GOV

For business resources: ITDPROJECTS.ORG/I84Businessresources

Linden Street
How long will Linden Street be closed?
How long will Linden Street be closed?

The current closure will last until early 2022. Linden Street will close again in Spring 2022 to allow crews to complete work on the underpass bridge. All work on the bridge is expected to wrap up in Fall 2022.

Linden Street
Will there be any access on Linden Street for motorists and emergency responders?
Will there be any access on Linden Street for motorists and emergency responders?

There will be no access for motorists. The underpass is 24 feet wide and vehicle access would severely limit the amount of space for construction crews and equipment. Access will be maintained for emergency responders.

Linden Street
Will you widen Linden?
Will you widen Linden?

Linden Street is under the jurisdiction of the City of Caldwell. It will not be widened as part of the project to widen I-84.

Linden Street
Will I-84 be closed during the construcution for Linden?
Will I-84 be closed during the construcution for Linden?

At least one lane of I-84 will be open during construction at the Linden Bridge underpass. All lanes will be open during the day.

Linden Street
How long will it take to use the detour for the Linden Street closure?
How long will it take to use the detour for the Linden Street closure?

The detour route will take approximately 15 minutes.

Variable Speed Limits
What are variable speed limit signs?
What are variable speed limit signs?

New digital speed limit signs will be installed throughout the I-84 construction zone in Canyon County (about 6 miles). These signs will allow ITD to adjust the speed limit as needed, based on the level of activity in the work zone.

Variable Speed Limits
What will the speed limit be?
What will the speed limit be?

The regularly posted work zone speed limit will continue to be 55 mph. In areas where crews are not working near traffic, the speed limit will be raised to 65 mph. On rare occasions, the speed will be lowered to 45 mph.

Variable Speed Limits
Where will the new signs be located?
Where will the new signs be located?

ITD will place signs between Karcher Road (exit 33) and Franklin Road (exit 29) interchanges on:

  • Eastbound and westbound lanes of I-84
  • The on-ramps at Karcher and Franklin roads
Variable Speed Limits
How long will the new signs be up?
How long will the new signs be up?

The new signs will be installed in August 2021 and will be in place until construction is completed in 2023.

Variable Speed Limits
What are the advantages of variable speed limits?
What are the advantages of variable speed limits?

Variable speed limits have been tested in many other states. Past studies have shown that variable speeds:

  • Increase drivers’ compliance with the speed limit.
  • Increase safety in the work zone for motorists and construction workers.
  • Improve overall travel times.
Variable Speed Limits
How will ITD decide when to change the speed? Who is in charge of this decision?
How will ITD decide when to change the speed? Who is in charge of this decision?

ITD will coordinate with the contractors and crews each week to determine speed limits.

Variable Speed Limits
Will speeds be lowered for the whole work zone or just one part?
Will speeds be lowered for the whole work zone or just one part?

The speed may vary from one part of the work zone to the next. This area of I-84 between Karcher Road and Franklin Road includes several different projects and contractors.

Variable Speed Limits
How will drivers keep track of the changing speed limits?
How will drivers keep track of the changing speed limits?

A flashing beacon will notify drivers when speed limits have been lowered ahead of time.

Variable Speed Limits
Has ITD done this in the past?
Has ITD done this in the past?

For some major work zones in the past, ITD has lowered the speed limit, when crews were likely to be working. This is the first time ITD has implemented a variable speed limit work zone through this corridor.

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