Resilience of New Jersey Transit (NJ TRANSIT) Assets to Climate Impacts
This report assesses the potential vulnerability of New Jersey's state transit agency (NJ TRANSIT) stationary assets (rail, structures and buildings) to weather-related risks and projected climate impacts and identifies “cost-effective resilience strategies.” While the assessment was underway, Hurricane Irene hit the state, causing $2 to $3 million in damages and losses in revenue and underscoring the need for NJ TRANSIT to plan for and build resilience against extreme weather events. The report quantifies the risks of a range of impacts to NJ TRANSIT assets given climate change scenarios over different planning timeframes (5, 10, 20 and 50 years).
First Environment completed the assessment by:
(1) conducting a literature review to identify relevant climate impacts,
(2) cataloging classes of assets at risk of particular impacts,
(3) mapping at-risk assets,
(4) developing indicators to determine the severity of impacts on assets,
(5) identifying resiliency measures, and
(6) developing cost estimates to support adaptation planning.
Through a literature review (of FHWA, FTA, IPCC and New York City Panel on Climate Change reports), the report identified the anticipated climate impacts for the region and developed the classes of NJ TRANSIT assets that are at risk. The classes of assets identified include: rails (light and heavy); structures (bridges, tunnels, culverts, and retaining walls); and buildings (offices, terminals, stations and platforms, depots, and cabins). Impacts considered include: increased temperature; sea-level rise and storm surge; and elevated storm frequency and intensity involving higher wind velocities, increased rainfall and lightning, increases snow levels per event, more frequent icing events, and increased flooding frequency and levels.
The report identifies anticipated climate changes for the region. First, maps were developed to assess the vulnerability of assets. The maps identified assets that are vulnerable to 100- and 500-year floods, storm surge, and falling tree limbs (Appendix 2). The assessment also developed risk indicators for climate projections, including: days over 90 degrees Fahrenheit, sea-level rise, and storm surge. The report presents projections for the frequency and severity of these events over the different planning horizons:
- Heat - using data from the Union of Concerned Scientists, the report estimates the increase in the number of days over 90 degrees for each planning time frame based upon IPCC emissions scenarios. The report projects an increase of 47 days for the 50-year planning horizon.
- Sea-level rise - using IPCC and Rahmstrof SLR projections, the report estimates a rise in sea levels of between 5.7-12.5 inches (IPCC) or 7.9-16.8 inches (Rahmstorf) by 2061 in the region.
- Storm/flood frequency - the report predicts an increase in both the frequency and intensity of storms over the next 20 years and beyond, concluding that the 100-year storm will become the 80-year storm.
The report discusses the possible impacts to NJ TRANSIT assets based upon these projections - finding that extreme weather events pose the greatest threat to NJ TRANSIT assets, particularly over the twenty to 50-year timeframe. Accordingly, the report uses a 50-year planning horizon for assessing vulnerabilities. One specific impact discussed is the elevated risk of rail buckling due to the increased frequency of days where the temperature exceeds 90 degrees Fahrenheit. It also discusses the impact of higher storm surges on bridge inaccessibility, scouring of retaining walls and bridges, culvert blockages, and salt water corrosion damage to structures. However, the report is careful to note that sea-level rise does not pose a substantial threat to NJ Transit over the next twenty years, but will “have crippling effects on assets beyond the 50-year planning horizon.”
The report lists potential strategies for building the resilience by asset across each of the predicted impacts (see summary tables in Appendix 1). For each strategy, the report estimates the costs of implementation. Some possible strategies for different types of assets include the following:
- Buildings: install emergency generators, install high temperature shade shelters, and increase ventilation in buildings.
- Rail: install expansion joints or anchors and ties to secure track and prevent buckling, revise specifications for equipment (such as transformers and signals) to withstand higher ambient temperatures, reduce electrical demand of rail operations and provide supplemental power feeds.
- Structures: increase tunnel ventilation
- Buildings: upgrade or replace existing systems, install seawalls, replace or relocate assets.
- Rail: replace existing track above sea level or if feasible construct a sea wall.
- Structures: seawall or replace structures, replace approach
Higher storm surges
- Buildings: repair or replace structures
- Rail: repair rail, rail bed and embankments; cancel services; repair electrical equipment and wiring; clear storm debris from rail tracks and rights of way
- Structures: increase maintenance and scour mitigation measures, stabilize soil embankments and harden existing retaining walls, increase maintenance or replace culverts, install pumps, barriers or gates in tunnels
Higher wind velocity
- Buildings: replace or reinforce roofs and windows
- Rail: repair electrical equipment and wiring, repair debris damaged lines, cleanup storm debris from tracks, require design changes for electrically powered rail lines
- Structures: evaluate adequacy of bridges to withstand increased pressure
- Buildings: repair or replace structures, clean drainage systems and install additional drainage
- Rail: stabilize embankments, build additional drainage, replace existing tracks above sea level, repair electrical equipment and wiring
- Structures: install additional culverts, increase maintenance of retaining walls and use scour mitigation measures
In conclusion, the report notes that NJ TRANSIT has experienced and can expect to experience more frequent weather-related impacts resulting in more frequent service disruptions. The report recommends that the agency prioritize its critical assets and select resilience strategies to implement over the coming years.
The assessment was conducted by First Environment under contract to NJ TRANSIT.
This Adaptation Clearinghouse entry was prepared with support from the Federal Highway Administration. This entry was last updated on October 31, 2015.
Publication Date: June 2012
- New Jersey (NJ) Transit