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Prototype / Demonstration Unit

A portable, temporary rig to demonstrate coordinated crosswalk illumination at an actual crossing. Not a permanent installation — a proof-of-concept that shows what activated illumination looks like from the driver's seat.

The goal: set up at a crosswalk after dark, activate the system, and let people see the difference. One evening of demonstration is worth every page in this repo.

What This Is Not

  • Not a permanent installation (no permits, no pole mounting)
  • Not the full spec (simplified power, no solar, no radar, no comms)
  • Not roadway-rated hardware (temporary demonstration only)
  • Not in the traveled way (all equipment on sidewalk/shoulder)

Minimum Viable Demo

Hardware List

Component Example Est. Cost Notes
LED emitters (5-10x) Cree CXB3590 or similar, 3-5W each, 15-25° optic $50-100 3000K or 4000K; total ~2,000-3,000 lumens is enough for demo
LED driver Mean Well HLG-120H-48A or similar, 48V CC $40-60 Constant current, dimmable
Battery 48V 10Ah LiFePO4 (or 4x 12V in series) $150-300 10Ah is overkill for demo — runs for hours of activations
Mounting bracket Aluminum L-bracket or unistrut, custom bent $20-40 Holds emitters in a line, adjustable aim per emitter
Tripod/stand Heavy-duty light stand, 10-15ft $80-150 Telescoping, sandbag-weighted. Not 25ft — demo doesn't need full height
Push button Momentary push button, 10ft lead $10 Manual activation for demo. No radar needed.
Timer relay 12V timer relay module, 20-second hold $15 Keeps light on for 20 seconds per button press
Wiring 14 AWG stranded, connectors, fuse holder $20-30 Inline fuse on battery circuit
Total $385-705

Assembly

  1. Mount 5-10 LED emitters on the bracket in a line, spaced 2-3 inches apart. Each emitter has its own narrow optic (15-25°).

  2. Wire emitters in series-parallel to match the LED driver's output voltage and current. With 48V driver and ~3V forward voltage per emitter, a series string of 12-14 emitters works, or parallel strings of 4-5.

  3. Connect LED driver output to the emitter string. Connect driver input to battery through the timer relay and push button: button press → relay energizes → driver powers on → emitters illuminate → relay holds for 20 seconds → de-energizes.

  4. Mount the bracket on the light stand at 10-15ft. Aim emitters down and back toward where the crosswalk will be.

  5. Split aim: angle lower emitters at the pavement (Zone A demo), upper emitters at ~4ft above the ground (Zone B demo). This is the core concept you're demonstrating — pavement AND person.

Setup at Site

  1. Choose a crosswalk you can access safely from the sidewalk. A campus crosswalk after low-traffic hours is ideal. Do NOT place any equipment in the roadway.

  2. Set the stand on the sidewalk, 10-20ft ahead of the crosswalk on the approach side. Sandbag the base.

  3. Aim the bracket back toward the crosswalk. Adjust individual emitters for Zone A (pavement) and Zone B (body height).

  4. Wait for dark. Press the button. Watch the crosswalk light up for 20 seconds.

  5. Have someone walk through the crosswalk during activation. Stand where a driver would be (200ft back on the approach) and observe the difference.

What You're Showing

  • Without activation: The crosswalk is dark. The person is a shadow. You might see the RRFB flashing but you can't see the pedestrian.
  • With activation: The crosswalk surface glows (Zone A). The pedestrian's body is lit from the front (Zone B). You see a person, not a shadow.

This is the 10-second pitch that no document can make.

Recording the Demo

A phone video from the driver's approach position (200ft back) showing:

  1. The dark crosswalk with a person in it (hard to see)
  2. Button press / activation
  3. The crosswalk and person lit up
  4. The person crossing while illuminated
  5. Ramp-down after clearing

That video, linked from the repo, demonstrates the concept faster than anyone can read the spec.

Intermediate Demo (adds radar activation)

If you want to show automatic activation (no button press):

Component Example Est. Cost
Radar sensor RCWL-0516 microwave motion sensor $5-10
Microcontroller Arduino Nano or ESP32 $10-20
Relay module 5V relay for switching LED driver $5

Wire the radar sensor to the microcontroller. When motion detected, energize the relay for 20 seconds. The pedestrian walks toward the crosswalk, the light activates automatically before they step off the curb. No button press needed.

This adds ~$20-35 to the build and demonstrates the passive detection concept.

What This Proves

  1. The lighting concept works — narrow-beam activated illumination from an offset position creates positive contrast on the pedestrian
  2. Dual-zone targeting works — Zone A lights the pavement, Zone B lights the person, visible from driver approach distance
  3. The cost is trivial — a demo unit costs under $700 in parts
  4. It's simple — LEDs, a battery, a timer. No exotic technology

What This Doesn't Prove

  • Actual illuminance levels (need a lux meter and proper mounting height to verify 20 lux)
  • Durability or weather resistance (demo hardware is not roadway-rated)
  • Solar viability (demo runs on battery only)
  • Long-term maintenance (demo runs for one evening)
  • Driver yielding behavior change (requires the full study design)

The demo proves the visual concept. The spec handles everything else.

Safety Notes

  • All equipment on sidewalk/shoulder. Nothing in the traveled way.
  • Battery is fused. No exposed terminals.
  • The light is aimed at the crosswalk, not at drivers. Confirm no glare from the approach direction before running the demo with live traffic.
  • If demonstrating at a crossing with active traffic, have spotters and wear high-vis. You are pedestrians, not traffic control.
  • This is a demonstration, not an installation. Remove all equipment when done.