Case Study

Realizing Co-Benefits of Multimodal Roadway Design and Gray and Green Infrastructure

Explore on-the-ground examples of communities improving pedestrian and bicycle networks as co-benefits to building resilience.

Year

2021

Details

Hazards

Flooding – General

Assets

Transportation and Mobility

Sources

DOT Federal Highway Administration

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Organizations

DOT Federal Highway Administration

Relevant Options

Develop agreements with Uber and other ride share platform drivers to provide emergency egress and evacuation services to residents and community visitors vulnerable to road access issues. Ensure there are alternate routes identified for emergency service vehicles during floods and landslides. Develop a coordination plan to clear roads from debris after disasters.

Coordinate with regional transit providers to identify alternative routes and stops if normal infrastructure is damaged or closed as a result of extreme events.
Develop a flood early warning system that uses gauges in strategic locations to monitor water levels. The system would provide alerts when roads may be flooding. Use the system to let people know when
Consider opportunities to add multi-modal transportation options (e.g., walking, biking, transit, rail) to areas isolated by threats. Consider how multi-modal transportation options can serve as an additional
Increase the use of bridges and multi-culvert installations (instead of single culverts) when possible to increase flow rate and enhance riparian areas.
Create a map of detours and educate the public on alternative access points and the evacuation plan. Ensure drafted communications include instructions on preparing to be temporarily stranded.
Design roadways, bridges and utilities with protective measures (e.g., elevate bridges, build protective berms) to account for future flooding projections.
Assess culvert structures for structural integrity on flood-prone streets in neighborhoods that could become isolated if a culvert were to fail.
Include rail lines and airports in the communication strategy when flood waters are rising rapidly.
Address flood-prone roads by installing green stormwater practices.
Use the best available science and resilient design features in transportation infrastructure to improve resiliency to extreme climate events.
Enhance emergency communication capabilities and evacuation strategies, routes and safety zones.
Develop a formal parking plan when there is a chance of flooding. Include appropriate signage on streets.
Incorporate information on bridge and road vulnerability to erosion, flooding and landslides into capital improvement planning processes.
Create a map of detours and alternate bus routes that factors in areas with recurrent flooding. Create a communications plan for altered or reduced service.
Coordinate with state officials to clear debris from state roads.
Diversify the fuel sources used by essential fleet vehicles to allow for travel in the event of a long interruption in the fuel supply. Examples include electricity, natural gas, propane and ethanol.
Use local climate projection data to understand the risk of failing culverts in future years. Weigh the economic, societal and environmental costs against the benefits of installing new culverts.
Replace older bridges and elevate them, if needed. If elevation isn't possible, explore other design solutions.
Create a backup communications plan and a road access plan for residents who rely on public transportation to access medical care (e.g., dialysis patients, the aging community, persons with disabilities)
Collaborate with rail lines and airports to identify and address critical flooding areas (i.e., capital projects for stormwater infrastructure adjacent to rails, culvert improvements, etc.).
Prevent building new roads in flood-prone areas.
Identify and improve key transportation and evacuation routes vulnerable to current or future flooding and other weather events.
Update local government maintenance protocols to prepare for climate vulnerabilities.
Ensure alternate transportation facilities (e.g., trails, separated bike paths, sidewalks) are available to enable impacted residents to access public services and health services without requiring a
Expand electric fleets, charging infrastructure, and energy backup to reduce emissions and support emergency response services.
Build private public partnerships that add, improve and connect more trails to parks.
Replace asphalt and concrete with bricks (i.e., permeable pavers) on roads and walkways to allow water to pass through.
Model the impacts of new transportation projects on hydrological processes and mitigate flood risk in the surrounding areas.
Identify opportunities to improve how public and private projects are designed. Keep flooding and sea level rise in mind.
Develop a local funding mechanism (e.g., gas tax or tax increment financing) to provide dollars towards non-capacity transportation projects.
Create agreements with AirBnB and other home share platforms to educate guests on hazards and emergency exit strategies.
Consider using highwater alert technology to prevent injuries and loss of life.
Launch a “Green Alleys” program. The program could offer garden materials and help coordinate volunteer labor to residents wanting to convert neighborhood alleyways to green space or green infrastructure.
Require that new development develop a transportation access plan to ensure that are multiple ingresses and egresses.
Identify funding for increased operation and maintenance costs for bridges. As temperatures increase and flooding and erosion becomes more frequent, maintenance costs will increase.
Ensure that any existing or newly permitted public facilities and services are designed to consider current and future flood scenarios when calculating level of service and are required to avoid present
Encourage federal authorities to consider issues of critical access when establishing standards of rail design.
Test new technologies, materials and tools to increase flood preparedness. For example, test inflatable flood barriers.
Coordinate with community members, transportation agencies and private entities to identify local and regional transportation, transit and active transportation corridors that are at-risk from climate
Test new technologies, materials and tools to increase preparedness for power outages during extreme weather. For example, test various means of backup power to protect traffic-control facilities, including
Require transportation access plan agreements for all large developments.
Encourage local government departments and local employers to offer remote work during extreme weather events to make economic activity and critical services less vulnerable to disruption.
Require access-limited communities to have a right-of-way access point that can used during an emergency (e.g., a greenway with bollards that lower for driving when flood occurs).
Bridge supports are weakened by the erosion of the underlying streambed. Strengthening these supports will prevent further damage to bridges and increase bridge resiliency during floods and storms.

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Realizing Co-Benefits of Multimodal Roadway Design and Gray and Green Infrastructure

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