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Assessment of Transportation Network Resilience and Safety Under Hazards to Project Level Bridge Performance


A resilient and cost-effective transportation network depends on a qualitative and quantitative assessment of the potential hazards, needs and benefits not only of the individual assets but also of their connectivity, redundancy and level of service as a whole. At present, bridge managers do not have a tool for assessing, comparing and optimizing the effect of project-level performance on a corridor or a network. Recent research has addressed consequences due to specific threats, such as natural hazards [1], work zone impacts [2], and the economic impacts of making functional improvements to a set of bridges along a corridor [3]. National Cooperative Highway Research Program (NCHRP) 46-11 integrates the hazard assessments and responses associated with extreme events [4]. Relevant studies have addressed multi-objective optimization [5] and the network costs of overweight truck traffic [6].

The need for a network level approach to the optimal allocation of constrained resources is exacerbated by relatively new demands of transportation safety and security. The subject is considered in NCHRP 20-7, Task 151 [7, 8]. Security considerations are, in general, addressed on the network level. In the meantime, project level analysis must address risk, site planning, component hardening, and traffic impact. These tasks are common to all hazards, but their source, mitigation, and level of urgency are different. For example, in one case the demand may derive from the structural condition, in another – from its functional importance, and in still another – from its vulnerability.


The deliverable of this proposed project will be a bridge management software tool. The network-level resilience and safety will be assessed under alternative fund-allocation strategies. The consequences of project-level measures for hazard mitigation and performance enhancements to a corridor or the network will be compared under a variety of hazards. All currently recognized sources of potential service failure will be considered, including natural hazards, structural deficiencies under normal service conditions, and deliberate acts of destruction. The software will be capable of including new constraints. The individual assets will be integrated into the transportation network according to their vulnerability, importance, redundancy, cost, and other criteria selected by the owner. Sets of localized enhancements will be compared in order to determine short and long-term network-level investment strategies. The outcome will be a capability to analyze the network resilience and safety as a function of the same criteria on the project-level.


This effort would serve as a guide to states and other agencies managing bridge

networks, and would be useful in the development of future transportation network models.

Related Research:

1. Adey, B.T. and Rade Hajdin, Incorporating Natural Hazards into Bridge Management Systems, in Bridge Maintenance, Safety, Management and Cost: Proceedings of the Second International Conference on Bridge Maintenance, Safety and Management, 2004.

  1. Hajdin, Rade and Bryan T. Adey, Algorithm to Determine Optimal Highway Worksites Subjected to Distance and Budget Constraints, presented at the 84th Annual Meeting of the Transportation Research Board, 2005.

  2. Oregon Department of Transportation Economic and Bridge Options Team, Oregon Department of Transportation Economic and Bridge Options Report, Appendix D, 2003 (http://www.oregon.gov/ODOT/ COMM/bridge_options.shtml).

  3. A. Alipour, NCHRP 46-11. Post-Extreme Event Damage Assessment and Response for Highway Bridges.

  4. NCHRP Project 12-67, Multiple-objective optimization for BMS.

  5. NCHRP 12-51 Effect of truck weight on bridge network costs.

  6. Science Applications International Corporation, Guide to Updating Highway Emergency Response Plans for Terrorist Incidents.

  7. Science Applications International Corporation, Guide to Highway Vulnerability Assessment for Critical Asset Identification and Protection.


The safe and cost-effective management of a transportation network requires a qualitative and quantitative assessment of the potential hazards, needs and benefits not only of the individual assets, but also of their connectivity, redundancy and level of service as a whole. It is proposed to develop a software tool for assessing the potential hazards to the network serviceability and safety, and optimizing the costs and benefits of their mitigation as a function of project level decisions.

The project will include the following steps:

  1. Create a transportation network inventory, consisting of multiple links and assets. Existing such inventories should be studied and used as prototypes to the extent applicable.
  2. Create a link to the AASHTO element level bridge condition software.

  3. Create an inventory of hazards and respective vulnerabilities. The NYSDOT set of vulnerabilities is one possible example.

  4. Create an inventory of mitigation options and their costs.

  5. Model the connectivity of the assets and their importance to network-level service. A corridor prioritization should be a feature of the model.


The user community for this research includes state and local bridge owners, bridge engineers, planners, and researchers in bridge management and operations research.The results of this research can be implemented in bridge management systems in the U.S. and abroad. The research should be conducted with an emphasis on developing a practical set of models and approaches to incorporate into existing bridge management systems, while recognizing the additional data and system requirements that may be implied by new approaches.


Many state transportation departments are using bridge management systems to help predict future conditions and allocate bridge funds. It is well understood that considering corridor and network effects may have a significant impact on BMS results. The systems currently in use fail to account for these effects, leading to potentially sub-optimal decisions. At this time, existing BMS are undergoing important upgrades nationwide. It is therefore appropriate to address the overdue transition from project to network-level hazard mitigation and performance enhancement.

Sponsoring Committee:AKT50, Bridge and Structures Management
Research Period:24 - 36 months
Research Priority:Medium
RNS Developer:Bojidar Yanev, D. Sc., P. E.; Executive Director, Bridge Inspection & Management, NYC DOT
Source Info:AHD35 Bridge Managament
Date Posted:01/29/2016
Date Modified:02/23/2016
Index Terms:Safety, Bridge management systems, Networks, Optimization, Resource allocation, Hazards, Transportation corridors, Traffic, Impacts,
Cosponsoring Committees: 
Maintenance and Preservation
Planning and Forecasting
Security and Emergencies
Bridges and other structures

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