Engineering Design Brief Creator

Engineering Design Brief: Pedestrian Footbridge

Problem Statement

The busy highway near the local high school poses a significant safety risk for students and pedestrians who need to cross. A new pedestrian footbridge is required to provide a safe, accessible, and efficient means for people to cross the highway without impeding traffic flow.

Goals and Objectives

• Provide a safe crossing for pedestrians, especially high school students, over the busy highway
• Ensure the bridge is fully accessible for people with disabilities
• Design an aesthetically pleasing structure that meets city council preferences
• Minimize traffic disruption during construction
• Complete the project within the allocated budget and timeline

Project Scope

• Design and construct a pedestrian footbridge spanning the width of the highway
• Bridge must meet all applicable safety standards and building codes
• Ramps and/or elevators to be incorporated for accessibility
• Lighting to be integrated for nighttime visibility and safety
• Decorative elements to be included based on city council input
• Deliverables include: design drawings, engineering calculations, budget, project schedule, and the constructed footbridge

Stakeholders

• Local high school students and staff
• Residents of the neighborhood
• City council and planning department
• Department of Transportation
• Construction company and engineering firm

Technical Requirements & Constraints

• Bridge must span 200 ft across the highway with a minimum clearance of 17 ft
• Weight capacity to accommodate peak pedestrian traffic of 100 people
• Designed to withstand local wind loads and seismic activity
• Materials must be durable, low-maintenance, and corrosion-resistant
• ADA compliant ramps with a maximum slope of 1:12
• Pedestrian guardrails at a minimum height of 42 inches
• Construction limited to non-peak traffic hours to minimize disruption

Operating Environment

The footbridge will be located in an urban setting over a high-traffic 6-lane highway. It will be exposed to outdoor weather conditions typical for the region, including high winds, heavy rains, and freeze-thaw cycles in winter. The bridge will be used primarily during daytime hours but must be safely operable 24/7.

Success Criteria

• Bridge passes all safety inspections and load tests
• Positive feedback from high school and community on aesthetics and ease of use
• No pedestrian accidents or injuries reported
• Bridge completed on time and within 2% of budget
• Traffic impact during construction minimized

Design Approach

1. Conduct site survey and soil analysis
2. Develop 2-3 conceptual designs for city council review
3. Select preferred concept and refine design
4. Perform detailed engineering analysis and calculations
5. Create construction documents and technical specifications
6. Obtain necessary permits and approvals
7. Procure materials and retain construction team
8. Construct footbridge in phases to minimize traffic impact
9. Conduct inspections and load testing prior to opening
10. Handover to city with as-built drawings and maintenance manual

Risks & Assumptions

• Geotechnical risk: poor soil conditions could require deeper foundations
• Material cost escalation could impact budget
• Construction delays due to inclement weather
• Assumption: city council will approve one of the proposed designs
• Assumption: all required permits will be granted in a timely manner

Budget & Timeline

• Design & Engineering: $250,000 - 3 months
• Permitting & Approvals: $50,000 - 2 months
• Construction: $1,500,000 - 6 months
• Inspections & Handover: $50,000 - 1 month
• Contingency (15%): $277,500
• Total Budget: $2,127,500
• Total Duration: 12 months

Next Steps

1. Present this design brief to city council for review and approval
2. Retain geotechnical engineer to begin site survey and soil analysis
3. Develop conceptual designs for city council consideration
4. Refine project timeline and budget based on selected design
5. Initiate permitting process and procurement of key materials

The engineering team looks forward to working with all stakeholders to deliver a safe, accessible, and aesthetically pleasing pedestrian footbridge for the community.