Decision Support Framework and Parameters for Dynamic Part-Time Shoulder Use:
Considerations for Opening Freeway Shoulders for Travel as a Traffic Management Strategy

Appendix A. Part-Time Shoulder Use Questions

1. Planning and Preliminary Engineering
   1. Is there any regional opposition to part-time shoulder use (PTSU)?
   2. Will physical roadway conditions permit PTSU?
   3. Is the shoulder pavement strong enough to carry traffic?
   4. Will the right or left shoulder be used?
   5. Is the segment long enough to provide meaningful congestion relief?
   6. Will the PTSU be bus-only, static, or dynamic?
   7. Has an operating scheme been selected?
   8. Will vehicle use restrictions (such as a prohibition on large/commercial trucks) be used?
   9. Is realtime monitoring and incident response in place?
   10. Does the corridor have supporting transportation systems management and operations (TSMO) and Traffic Incident Management (TIM) capabilities in place?
   11. Does PTSU significantly reduce cost compared to a traditional capacity expansion?
   12. Has project been incorporated into Transportation Improvement Program (TIP) and long-range plan?
   13. If an area has a congestion management process (CMP), is shoulder use a compatible strategy?
2. Mobility Analysis
   1. What is a reasonable estimate of capacity for the shoulder?
   2. What tools will be used for operations analysis?
   3. Will part-time shoulder use improve reliability?
3. Safety Analysis
   1. What types of crashes are occurring today?
   2. Are there congestion-related crashes that PTSU could reduce?
4. Environmental Analysis
   1. Is there concern about the project within the community?
   2. Should air quality analysis be conducted?
   3. Is the project in a non-attainment or maintenance area?
   4. Is the project in a state that requires greenhouse gas analysis?
   5. Will any sensitive noise receptors be impacted?
   6. Should noise analysis be conducted?
   7. Will there be physical widening that potentially impacts water resources, plants and animals, cultural and historic sites, etc.?
   8. Does the project meet the criteria for a categorical exclusion?
5. Costs and Benefits Analysis
   1. Are operations and maintenance costs being included in cost estimates?
   2. What benefits will occur and how are they being monetized?
   3. Does the benefit-cost analysis take into account the ability to deploy PTSU much quicker than adding capacity?
6. Roadway Design
   1. Are there good locations to begin and end shoulder use that don't create bottlenecks themselves or safety issues?
   2. Has compliance with Controlling Criteria been assessed?
   3. How wide will the shoulder be?
   4. Are there bridges or other areas where the shoulder will be narrower?
   5. Has vertical clearance under bridges been checked?
   6. Have drainage patterns been checked? Sometimes the shoulder is used to store water or facilitate drainage with irregular cross slopes.
   7. Has stopping sight distance been checked on curves adjacent to barriers?
   8. Have fixed object offsets been checked? Guardrails, signs, and other objects may need to be moved further away from the roadway.
   9. Have clear zones been checked? New guardrails may need to be installed.
   10. Are there objects such as bridge piers that cannot be moved, and how will shoulder traffic pass through these areas?
   11. Are ramps taper-style or parallel-style and will any need to be modified?
   12. Are there any two-lane entrance or exit ramps that exist today?
   13. Are there system interchanges?
   14. Will PTSU pass through larger interchanges or terminate on a ramp?
   15. Are modifications needed at any ramp-freeway junctions?
   16. Will safety turnouts be provided and have locations been established?
   17. Should a second edge line be added on the outside of the shoulder?
   18. Are dynamic signs needed, whether they be supplemental or primary?
   19. Is signing and pavement marking compliant with the Manual on Uniform Traffic Control Devices (MUTCD)?
   20. What ITS infrastructure should be added to aid facility operators or provide mitigating strategies?
   21. Will other TSMO strategies be implemented as a mitigation for design exceptions?
7. Implementation
   1. What design exceptions are needed and have they been processed? At a minimum, an exception for shoulder width is necessary.
   2. Is an MUTCD Request for Experiment necessary?
   3. Are stakeholders such as police and emergency responders engaged?
   4. Have state-specific legal issues such as laws prohibiting driving on the shoulder been addressed?
   5. Is public outreach plan established?
8. Maintenance and Operations
   1. Are communication mechanisms in place between police, emergency responders, and facility operators?
   2. Is an incident management plan in place?
   3. Do police have a plan for conducting enforcement?
   4. Is there a plan for plowing snow from the shoulder?
   5. Is there a maintenance plan for aggressive debris removal from the shoulder since it will be used for travel at times?
   6. Will there be other unique maintenance needs and have they been addressed?
   7. What specific actions will occur each time the shoulder is opened or closed?
   8. Have responders established preferred response procedures to incidents when the shoulder is open to traffic?
   9. Have a protocols been established to decide to close the shoulder during certain incidents?