Department of Transportation


I-80 Rockfall Mitigation Photo

Frequently Asked Questions

What parts of I-80 are included in the study?
The project site is located along the westbound lanes of Route 80, between milepost 1.04 and milepost 1.45 in the vicinity of the Delaware Water Gap. The proposed project is located in Hardwick and Knowlton Townships, Warren County, New Jersey. Please follow this link for a map of the project area.
Will any private property or business owners be impacted?
All work will occur within the NJDOT owned right-of-way. There will be no property acquisitions.
What is the extent of NJDOT right-of-way in the Project Area?
NJDOT owns and maintains property along I-80 which extends north 100 feet from the center line of the I-80 roadway into the rocky slope, which is located along the existing concrete median barrier, and extends south to the mean high-water line along the Delaware River.
When was I-80 constructed in this location?
• Prior to the roadway use, the I-80 corridor was part of a branch railroad corridor operated by the Delaware, Lackawanna, and Western Railroad (DLW) from at least 1887 to 1952. A freeway along the I-80 corridor was first planned in 1936. The initial corridor was intended to supplement US Route 46 and extend from the George Washington Bridge west to the Delaware Water Gap and Scranton, Pennsylvania (Source: “Freeways Are Now Urged.” The New York Times. December 13, 1936). By 1953, a portion of this route between the Delaware Water Gap and Columbia had been constructed. In 1955, it was proposed that a new highway, the Bergen-Passaic Expressway, would relieve congestion on Route 4 and US 46 and extend from the George Washington Bridge to Paterson. The following year, the continuation of this road to the west towards the Delaware Water Gap was recognized as Federal Aid Interstate Route 101 by the New Jersey State Highway Department. Originally designated I-82, the route, which was identified as I-80 by 1958, was defined to include the Bergen-Passaic Expressway and to parallel US 46, extending from the Delaware Water Gap to the George Washington Bridge (Source: Wright, George Cable (March 5, 1958). “Jersey Acts To Speed U.S. Aid for Its $388.5 Million Freeway.” The New York Times).
Who owns I-80?
I-80 is a major interstate highway in the United States, running from the New York City Metropolitan Area westward to San Francisco, California. I-80 in New Jersey runs 68.54 miles (110.30 km) from the Delaware Water Gap Toll Bridge over the Delaware River at the Delaware Water Gap to its eastern terminus at I-95 in Teaneck, Bergen County. The section of highway that travels through New Jersey is owned and maintained by NJDOT.
How many cars travel through the Delaware Water Gap on I-80?
Approximately 51,000 vehicles per day pass over the Delaware Water Gap Toll Bridge in both directions, based on data from the Delaware River Joint Toll Bridge Commission’s 2018 Annual Report. This equates to about 18.5 million vehicles per year passing through this segment of I-80 and the southern portion of the Delaware Water Gap National Recreation Area (Source: 2018 Annual Report Delaware River Joint Toll Bridge Commission).
What is the purpose of this project?
The purpose of the I-80 Rockfall Mitigation Project is to increase safety and improve the mobility of the traveling public by reducing the frequency and severity of rockfall events.
Why is this work necessary?
The existing rock cut areas along the westbound lanes of I-80 within the project limits exhibit physical and geological safety hazards. The primary modes of rock instability identified during the data collection and site characterization of the area include planar sliding, wedge sliding, toppling, and discrete rockfall as evidenced by the large overhangs, steep vertical faces, loose boulders, and rock blocks, which have resulted in rock toppling down and landing on the shoulder and roadway lanes along the I-80 roadway. A series of large open fissures exists in the area near the steep vertical rock wall, and if these fissures are not stabilized, there is the potential for a major rockfall incident to occur. This I-80 segment, between mileposts 1.04 and 1.45, has been characterized as having the highest rockfall hazard rating scores (i.e., highest risk) in New Jersey based on the Rockfall Hazard Management System that was developed by the Federal Highway Administration (FHWA).
How is rockfall analyzed?
The FHWA Rockfall Hazard Rating System (RHRS) is intended to be a tool that allows transportation agencies to address their rockfall hazards proactively instead of simply reacting to rockfall accidents. The RHRS provides an objective, standardized way to prioritize the use of the limited construction funds available by numerically differentiating the apparent risks at rockfall sites. This proactive approach has been developed and adopted by the FHWA and is the accepted industry standard throughout the United States (Source: Rockfall Hazard Rating System Participant’s Manual, NHI Course No. 130220, Publication No. FHWA SA-93-057, November 1993).
If the proposed improvements in Areas C and D were removed from the project, would this location still be rated as the #1 rockfall hazard location in New Jersey?
If the proposed improvements in Area C and D were not constructed, then this location would still be rated as the highest rockfall hazard location in the state. Additionally, the rating along each individual segment of this slope is high enough to warrant mitigation. Therefore, the four project areas have been grouped together as a single project rather than four individual projects to minimize impacts to traffic, improve constructability, and reduce cost.
Have there been any vehicle crashes within the Project Area that resulted from rockfall?

Between 2001 and 2018, there have been 14 crashes that resulted from rockfall activity (13 from fallen rocks and one from a fallen tree). Of this total, there was one crash that resulted in one fatality and one minor injury.

For detailed information on the crash data, please follow the website link provided below: https://www.nj.gov/transportation/refdata/accident/distributioncenters.shtm
Who will pay for the proposed project?
The I-80 Rockfall Mitigation Project is being funded using federal resources.
Why did the cost for this project increase from the original estimates and what is the current estimated project cost?
The original alternatives were intended to incorporate removal and stabilization of source material from areas much farther upslope within areas under the jurisdiction of the National Park Service (NPS). The NPS formally responded in April 2016 with their preference that proposed mitigation be confined within the right-of-way of I-80 and not encroach upon federal lands. Accordingly, a series of revised alternatives that remained within the I-80 right-of-way and continued to meet the project purpose and need were developed. However, in doing so, the strategies employed are much more complex mitigation systems than regularly encountered on a project of this type. Similarly, these more robust alternatives introduced greater project costs as well. In addition, based on comments from the public and from project stakeholders, the design has evolved to incorporate additional mitigation measures in order to minimize impacts. By doing so, the cost has been increased to reflect the more complex design and construction requirements. The Preliminary Preferred Alternative is estimated to cost $47 million.
Why are you spending federal funds on this project when the S-curves are the real problem?
Federal funds disbursed to New Jersey are assigned to various asset categories. The federal funding that would be used for this project is from dollars that are allocated for rockfall hazard mitigation projects. If this project was not constructed, the money would be reallocated to another rockfall hazard project within the state.
Why can’t NJDOT fix the S-curves?
NJDOT is aware of local concerns along this stretch of roadway. We are investigating these concerns and considering roadway and driver enhancements using available innovative technologies that could improve driver attention and safety. In 2020, in response to these concerns, NJDOT installed new speed limit signs and warning signs with flashing lights and completed a pavement improvement project along the S-curve segment.
Will blasting be necessary and when will blasting occur? Will it require the road to be closed?
Blasting is necessary in order to trim back the existing slopes in Areas A and B to create the catchment ditch. Blasting is anticipated to occur once per week (Monday through Thursday) between May 15 and September 15 (except holidays) to be completed in one construction season. Blasting activities will be scheduled and publicly advertised to the traveling public in advance. Blasting will require complete traffic stoppages for 15-minute intervals. All blasting operations will comply with regulations set forth in N.J.A.C. 12:190 and N.J.S.A. 21:1A-128, which regulate the use of explosives.
What if there is an emergency when the road is closed for blasting; how will emergency services be able to get through?
NJDOT continues coordinating with local emergency services to develop and implement emergency response strategies that will continue to the conclusion of the project. An Emergency Services Task Force will be formed that will include representatives from local emergency services, in both New Jersey and Pennsylvania, to address local and regional incident management and operations concerns. Plans will be developed for continued service during construction activities such as blasting. NJDOT would also implement several measures to monitor and protect traffic during construction in order to avoid and minimize potential impacts to I-80 and local roadways in both New Jersey and Pennsylvania.
Will there be any detours during construction?
The proposed project would not require any planned detours; the existing four lanes of traffic (two lanes in each direction) along I-80 would be maintained during peak hours of travel during construction. Single-lane closures following NJDOT Standard Lane Closure Hour guidelines would occur during periods of lowest traffic volumes, primarily during the overnight hours.

Motorists would be notified of scheduled temporary lane closures and roadway stoppages so that drivers could make informed decisions regarding the use of alternative regional routes. A potential regional route has been identified as an alternative route to destinations west of I-80. For destinations west of the project site, motorists would be advised to utilize I-287, I-78, and PA State Road 33 (SR33).
Will the proposed project lead to traffic delays along I-80?
The goal of any construction project is to minimize disruption to the motoring public. Preliminary analysis of staging shows that both lanes of traffic along I-80 can be maintained during construction during peak hours of traffic. No planned detours or long-term lane reductions are being considered at this time. Occasional delays during off-peak hour temporary lane closure and roadway stoppage scenarios are anticipated during project construction. Traffic stoppages (limited to 15-minute intervals) would occur during off-peak hours for construction blasting activities and would be controlled by the New Jersey State Police. These stoppages would be short in duration and unrestricted travel would be restored once the blast and clean-up are complete. Blasting activities are anticipated to occur before 12:00 PM where delays would be around 25 minutes or less. Blasting is anticipated to occur once per week (Monday through Thursday) between May 15 and September 15 (except holidays) during one construction season.

In an effort to minimize impacts to traffic during construction, NJDOT would continue coordination with PennDOT to provide regional coordination on traffic and construction activities in New Jersey and Pennsylvania including the proposed I-80 Reconstruction Project in Monroe County, Pennsylvania (located approximately five miles west of the Project Area), as well as other planned projects in the region, to anticipate and minimize potential traffic disruptions and delays.
Will the proposed project cause congestion on local roads in New Jersey and Pennsylvania?
No planned detours are anticipated that would divert traffic to local roads. Early analysis of staging shows that both lanes of traffic along I-80 can be maintained during construction during peak hours of traffic. Occasional off-peak hour temporary lane closures and roadway stoppage scenarios are anticipated during project construction. NJDOT would also implement several measures to monitor and protect traffic during construction in order to avoid and minimize potential impacts
What is the schedule?
The Preliminary Engineering phase (including preparation of the environmental document) is expected to be completed by 2021, and the Final Design phase (including permitting) is expected to take place in 2021/2022. Project construction is anticipated to start in 2023 and will last approximately four years.

Please follow this link to the project schedule webpage.
Will construction of this project be coordinated with other planned construction projects in New Jersey and Pennsylvania?
Coordination of this project with future projects in New Jersey and Pennsylvania is on-going to avoid conflicts between projects. NJDOT is coordinating with PennDOT to assure regional coordination on traffic and construction activities in New Jersey and Pennsylvania including the proposed I-80 Reconstruction Project in Monroe County, Pennsylvania, as well as other planned projects in the region, to anticipate and minimize any potential traffic disruptions and delays.
Will the reduced lane widths during construction lead to more accidents on I-80?
Lane width reductions will be implemented using proven state and federal safety standards for traffic control within construction zones. Current posted speed limits will also be reduced during temporary construction lane shifts, as needed to enhance safety. Additionally, lane designations for trucks will be investigated.
How will construction activities affect travel and tourism in the region?
The proposed project would maintain the existing four lanes of traffic along I-80 (i.e., two lanes in each direction) during peak hours of travel during construction in order to avoid and minimize potential impacts to regional and local travel through the Project Area. Any temporary lane closures would occur during periods of low traffic demand. In addition, no temporary lane closures would occur on Fridays from mid-May to early September and holidays would be avoided. NJDOT would also implement several measures to monitor and protect traffic during construction in order to avoid and minimize any potential impacts. The Project would not cause any displacement of businesses or individuals. In the long-term, the Project would improve the operations and safety of I-80 through the Project Area, thus maintaining access to local businesses and enhancing the region’s popularity as a tourist destination.
Will this project look like the Route 46 rockfall mitigation project constructed south of I-80?
Each and every rock slope has its unique characteristics and rockfall mitigation strategies are customized to meet the specific conditions and features of those slopes. In general, the alternatives under consideration do not include the same type of rockfall mitigation that was constructed for the Route 46 rockfall mitigation project, however, certain design elements may be employed, as necessary.
Will the proposed project affect the natural beauty of the Delaware Water Gap?
The NJDOT has engaged in ongoing consultation with the National Park Service, the New Jersey Historic Preservation Office, the Pennsylvania State Historic Preservation Office, the New Jersey Department of Environmental Protection (NJDEP), and tribal nations in order to develop measures to minimize visual impacts that may result from the proposed project. NJDOT has also held two public meetings and will continue to advance public involvement activities in order to solicit feedback from project stakeholders and the public in the development of aesthetic treatment measures. Measures incorporated to date in the project design in order to minimize visual impacts include the development of aesthetic treatment options that are in keeping with the color, scale, and material of the surrounding rock in the Project Area, such as the appearance of stone on the rockfall berm and the color of fencing and pinned mesh. NJDOT is also looking into several plant species that could be planted in the rockfall berm and surrounding area.
What are the environmental concerns?
Environmental issues that will be evaluated as part of the proposed project include threatened and endangered species, ecological resources, cultural resources, visual resources, noise and vibration, socioeconomic concerns, and hazardous materials, among others. For more information about the National Environmental Policy Act (NEPA) process, refer to 23 CFR 771 and https://www.fhwa.dot.gov/federal-aidessentials/catmod.cfm?id=39.
How will this project affect recreational users on the river and on park trails?
The proposed project would not impact parks, open space, or recreational resources, as the Project is located within the NJDOT right-of-way. It is expected that aside from limited times when blasting occurs, that recreational park uses would not be affected. Parking lots, trails, and river access will remain open. Parks, open space, and recreational areas would remain operational during construction of the Project. NJDOT would coordinate with NPS and NJDEP regarding any notifications for park users of planned blasting activities, as well as any potential short-term, temporary restrictions on hiking trails, rock climbing, and/or river activities during blasting.
How will this project affect hiking and rock climbing along Mount Tammany?
Publicly accessible trails within the Delaware Water Gap National Recreation Area and Worthington State Forest will remain open and accessible during project construction. Activities such as hiking and rock climbing along Mount Tammany and other popular locations, as accessed by properly identified park trails or facilities, would still be able to occur, following all applicable federal and state rules. NJDOT would coordinate with NPS and NJDEP regarding any notifications for park users of planned blasting activities, as well as any potential short-term, temporary restrictions on hiking trails, rock climbing, and/or river activities during blasting. In addition, NJDOT would consult with NPS and rock-climbing groups in order to develop strategies to allow for safe access to rock climbing in the vicinity of the Project Area during project construction as well as potential enhancements for access after project construction.
How are you protecting snakes in the Project Area?
NJDOT has been coordinating extensively with the NJDEP in the development of measures to minimize impacts to snakes and wildlife. In addition, there will be monitoring before construction and any identified snakes will be temporarily re-located. There also will be monitoring during construction. Consultation with the NJDEP regarding the development of minimization and mitigation strategies will be ongoing as the project advances into the construction phase.
Why did the project change from a Categorical Exclusion (CE) to Environmental Assessment (EA)?
Initially, the Project advanced as a CE under the National Environmental Policy Act; however, in May 2018, after conferring with FHWA, the National Park Service, and the NJDEP, NJDOT determined that preparation of an EA would be appropriate for the Project due to its unique location and to allow for additional public involvement.
Will NJDOT prepare an Environmental Impact Statement (EIS) for the project?
The analyses that are being conducted as part of the Environmental Assessment (EA) will, in fact, assist FHWA in making the determination as to whether the level of impacts warrant the preparation of an EIS. The EA and supporting technical environmental studies will be made available for public review and a Public Hearing will be held. Once public comments are received and evaluated, a determination of the significance of the impacts will be made. If FHWA, as the federal lead agency, determines that the project would result in significant impacts, an EIS will be prepared. If, after completing the EA, it is evident that there are no significant impacts associated with the project, a finding of no significant impact (FONSI) may be prepared.
What is NJDOT doing to fix the retaining wall along I-80?
NJDOT Maintenance and Operations performed a video evaluation and identified drainage pipe issues suspected of causing erosion at the retaining wall. In 2020, NJDOT completed repairs to a drainage pipe, inlets, and the retaining wall near milepost 1.4 along eastbound I-80.
What if there is another fire in the Delaware Water Gap—won’t the new wall and fence prevent access to put out the fire?
The proposed five-foot-high safety fence in Areas A, C, and D would include a gated entrance every 400 feet to allow emergency access to upland areas as well as providing access for NJDOT maintenance crews. The transitions zones at each end of the Project would also provide construction access to the project site and allow future access to upslope areas for emergency services.
How will the community be involved in this project?
NJDOT is committed to having an active, continuous public and community outreach effort on this project. NJDOT will continue outreach initiatives with elected officials, project stakeholders and local communities. NJDOT has formed a Public Advisory Group (PAG) that includes members of the public, user groups, and key business groups that are representative of the local communities affected by the project. The PAG has held working meetings to discuss project progress, issues of interest to the community, and to respond to community concerns. The PAG is anticipated to remain active throughout the duration of the project (Preliminary Engineering, Final Design, and Construction) and to serve as an active means to communicate and update project information, raise local concerns to the project team, and hear how they are being incorporated into the project development process. NJDOT is also creating an Emergency Services Task Force to coordinate emergency services issues with both New Jersey and Pennsylvania. In addition, a Public Hearing will be hosted by the NJDOT to share information about the project and to obtain community input.
How can I stay informed or offer suggestions?
You may:
  • Check the project website regularly for updated information
  • Attend the Public Hearing
  • Contact NJDOT via email at I80Rockfall@dot.nj.gov
What if I have other questions or concerns about the project?
The NJDOT encourages community members to voice their concerns and contribute suggestions to the Project Team. To provide input, attend one of the public meetings or send comments to:

New Jersey Department of Transportation
Office of Community Relations
1035 Parkway Avenue
Trenton, NJ 08625
(609)963-1982
I80Rockfall@dot.nj.gov

Last updated date: March 5, 2021 11:10 AM