Multi-Hazard Emergency Bridge Response at Scale

1. Agency Context

The Arkansas Department of Transportation (ARDOT) manages a large and diverse bridge inventory that is routinely exposed to multiple natural hazards, including flooding and seismic risk associated with the New Madrid Seismic Zone. Supporting emergency response across this network requires reliable emergency management software capable of providing early situational awareness, coordinated field deployment, and defensible decision-making during high-impact events.

Emergency response for transportation infrastructure in Arkansas depends on the agency’s ability to:

• Rapidly identify impacted structures
• Prioritize actions under uncertain and evolving conditions
• Deploy limited inspection resources efficiently
• Maintain consistent documentation to support operational and safety decisions

To meet these requirements, ARDOT uses emergencyX™, developed by AssetIntel™, and integrated with bridge inventory data, National Weather Service (NWS) forecasts, USGS stream gauge data, and USGS ShakeCast earthquake modeling to support both real-world emergency response and large-scale preparedness planning.

Photo Courtesy: 2025 AssetIntel™ Annual User Group meeting - ARDOT's Presentation of emergencyX™

Photo Courtesy: 2025 AssetIntel™ Annual User Group meeting - ARDOT's Presentation of emergencyX™

Photo Courtesy: 2025 AssetIntel™ Annual User Group meeting - ARDOT's Presentation of emergencyX™

‍

2. The Operational Challenge

ARDOT faced two distinct but related emergency-response requirements:

• Immediate response to real-world flood events, where access, safety, and timing are highly constrained
• Preparedness for high-consequence earthquake scenarios, requiring advance modeling, inspection scoping, and resource planning

Each hazard required a different workflow, but both demanded:

• Early situational awareness
• Defensible prioritization logic
• Coordinated field and office operations
• Repeatable inspection and documentation processes

Addressing both hazards required emergency management software capable of supporting real-time response while also enabling large-scale planning and preparedness activities.

3. Flood Event Response: April 2025 Storm

Photo Courtesy: 2025 AssetIntel™ Annual User Group meeting - ARDOT's Presentation of emergencyX™

3.1. Early Monitoring and Alerting

During the April 2025 storm event, ARDOT monitored weather and hydrologic conditions statewide using:

• National Weather Service (NWS) forecasts, watches, and warnings
• USGS stream gauge data
• emergencyX™ system notifications

The operational objective during the event was to ensure timely response for bridges with established Plans of Action (POAs) related to scour risk.

Early in the storm, ARDOT identified approximately 160 bridges with active POAs requiring heightened awareness. Under previous practices, monitoring flood conditions and initiating inspections relied largely on manual review of NWS alerts by districts or local owners, followed by independent field verification.

During a large, rapidly evolving storm event, this approach limited ARDOT’s ability to:

• Maintain consistent, statewide visibility of at-risk structures
• Coordinate response actions across districts
• Align inspection timing directly with POA requirements

Using emergencyX™, ARDOT was able to centralize weather monitoring and alert review through a single emergency management software environment, allowing flood conditions, bridge inventory data, and POA requirements to be evaluated together. This provided a structured basis for prioritization and enabled a coordinated transition from monitoring to field deployment as conditions evolved.

3.2. Alert Validation and Prioritization

As weather conditions evolved:

• 600–700 alerts were generated during the storm
• Each alert was reviewed and validated by ARDOT staff
• Alerts that did not reflect real-world conditions were rejected or marked as false alarms
• Approximately 400 structures were approved for further action

Approved structures were then grouped based on:

• Geographic location
• Predicted damage severity
• Known scour-critical status
• Presence of an existing POA

Additional groupings included:

• Structures susceptible to scour but considered stable
• Low-risk structures

This grouping allowed inspectors to focus on the most critical assets first while maintaining statewide awareness.

3.3. Field Deployment and Coordination

ARDOT coordinated seven field teams simultaneously, using emergencyX™ to:

• Draw polygon-based clusters around groups of bridges
• Dynamically assign inspection teams
• Track inspection progress in near real time

Office staff monitored field activity continuously, adjusted routing to avoid flooded roads, and identified locations where inspections would need to be deferred due to access or safety constraints.

Inspections were performed in clusters based on predicted impact and accessibility, improving:

• Response efficiency
• Inspector safety
• Coverage consistency

This level of coordination would not have been feasible without emergency management software designed to support dynamic assignment and real-time visibility during active events.

3.4. Inspection Execution and Documentation

For each inspected structure, inspectors were required to capture:

• Upstream and downstream channel photos
• All substructure units
• Evidence of scour or undermining
• Debris accumulation
• Measurements where applicable

Where access was limited, drone-assisted inspections were used.

Inspectors completed a standardized emergencyX™ inspection form, documenting:

• Channel condition and protection ratings
• Scour assessment requests
• High-water elevation
• Scour condition rating
• Overtopping likelihood
• Scour vulnerability
• Actions taken on site

Each data element allowed photo attachments and notes, ensuring consistency across all inspections. After fieldwork, engineers conducted post-event reviews and analysis.

3.5 Flood Outcomes and Follow-Up

Photo Courtesy: 2025 AssetIntel™ Annual User Group meeting - ARDOT's Presentation of emergencyX™

In several cases:

• Bridges were fully submerged, allowing only limited safety assessments
• High water and debris indicated possible active scour
• Structures were placed in monitoring status pending water recession

Follow-up inspections revealed:

• Severe damage to Abutment 1 at one structure
• Approximately 18 feet of undermining
• Significant soil erosion behind the abutment
• Large debris blocking the waterway

As a result, the affected bridge was closed until repairs could be completed.

4. Earthquake Preparedness and Response Planning

In parallel with flood operations, ARDOT uses emergencyX™ as its emergency management software to support earthquake response planning in coordination with USGS ShakeCast.

4.1 USGS and ShakeCast Integration

ARDOT collaborates with USGS experts, including:

• David Wald, PhD, USGS Seismologist and developer of ShakeCast
• Duo-Wan Lin, PhD, USGS Development Geophysicist and ShakeCast programmer

ShakeCast data is integrated with ARDOT’s bridge inventory to support earthquake impact modeling and inspection planning.

4.2 Impact Modeling and Asset Screening

Two complementary modeling approaches were used:

• Shotgun approach: Identifying all structures that would “feel” shaking
• Rifle approach: Using FHWA and USGS calculations to evaluate ground acceleration and expected impact on each bridge

Results included:

• Approximately 4,400 impacted structures statewide
• Separate analyses for state-owned and locally owned bridges
• Scenarios excluding culverts
• Color-coded impact potential (green, yellow, orange, red)
• Fault surface and ground motion contour overlays

4.3 Inspection Scoping and Resource Planning

From the modeled impacts, ARDOT narrowed the scope to 211 bridges requiring inspection.

Key characteristics of this inspection set included:

• Total deck area: 1,558,320 square feet
• Longest bridges: 50,899 square feet
• Shortest bridges: 740 square feet
• Average age: 58 years
• Oldest bridge: 97 years
• Newest bridge: 32 years
• Route types: Interstate, U.S. Highway, State Highway, County, and City
• Total ADT: 711,980

4.4 Time and Staffing Estimates

ARDOT developed conservative inspection estimates:

• 30–60 minutes per inspection to identify major damage
• Estimated 60-minute drive time between structures (most under 10 miles)
• 422 total working hours
• 10-hour working days (8 hours inspection time)
• 53 working days total (conservative)
• Assuming 20 of 29 crews mobilized

Under these assumptions, ARDOT estimated:

• 2.65 days to assess all 211 structures

5. Earthquake Inspection Execution Framework

Earthquake inspections are conducted using a modified, rapid inspection approach within emergencyX™.

Photo Courtesy: 2025 AssetIntel™ Annual User Group meeting - ARDOT's Presentation of emergencyX™

Inspectors apply color-based safety ratings:

• Green – Slight damage
• Yellow – Moderate damage
• Orange – Extensive damage
• Red – Complete damage

Inspection criteria address:

• Bearings
• Columns and piers
• Expansion joints
• Abutments
• Footings and pile caps
• Deck and approach settlement

Each element supports photo attachments and notes, enabling rapid safety determinations and clear documentation.

6. Results and Value to ARDOT

By using emergencyX™ for both flood response and earthquake preparedness, ARDOT achieved:

• Faster, more focused field deployment
• Reduced uncertainty during emergency conditions
• Improved inspector safety
• Consistent, repeatable documentation
• Defensible, data-supported decisions

The same platform supported real-world response and scenario-based planning without duplicating systems or workflows. By relying on a single emergency management software platform, ARDOT avoided fragmented workflows while maintaining consistency across both operational response and preparedness planning.

7. Looking Ahead

ARDOT plans to:

• Conduct annual or biennial emergency training events
• Run full-scale emergency scenarios, including earthquake simulations
• Maintain continuous flood and earthquake monitoring statewide

References:

This case study is developed from 2025 AssetIntel™ Annual User Group meeting - ARDOT's Presentation of emergencyX™.

‍