Flow Traffic · Flow Seattle

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Collective Impact

Flow Seattle · What the community is doing

🌐 Seattle community — this week

Estimated across all active Flow Seattle drivers who logged trips in the last 7 days. Each driver with a Flow Score above 70 contributes to phantom jam prevention based on their corridor's baseline data.

247

estimated phantom jams prevented

62% of weekly community goal (400 jams)

1,842

Collective hours saved this week

1,203

Active Flow drivers today

How this is calculated: Flow Traffic estimates phantom jam prevention by comparing each driver's braking smoothness score against historical baseline data for their corridor and time of day. A score above 70 indicates driving behavior that is unlikely to trigger a shockwave. Each prevented shockwave saves an estimated 15–40 vehicles from stop-and-go traffic lasting 10–45 minutes.

🗺 Corridor breakdown

Phantom jams prevented this week by route. Your corridor is highlighted. Side streets show high impact from I-5 Revive overflow.

👤 Your personal impact

Your contribution to the Seattle community, across all four scores.

Driver rank

New driver

Phantom jams prevented0

Drive Smart progress0 / 30 trips

Drive School

Washington State · Adapted from WA DOL Driver Guide

🌊

Module 1 · Phantom Jams & Following Distance

The foundation · Adapted from WA DOL Driver Guide

Unlocked

🔀

Module 2 · Merging & the Zipper

Washington's actual merge law — and why everyone's doing it wrong

Unlocks at 10 trips

🌧

Module 3 · Rain, Fog & PNW Conditions

Why Seattle weather changes everything about driving behavior

Unlocks at 20 trips

WA Law · Basic Rule of Speed

Washington's Basic Rule (RCW 46.61.400): driving the posted speed limit in bad conditions can itself be a violation. Conditions include rain, fog, ice, heavy traffic, and low visibility. You can be ticketed for driving 60 mph in a 60 mph zone if conditions don't support that speed.

🌊 Safety Score weather weighting: rain and fog automatically increase the score penalty for speed events. WaveGuard adjusts your scoring based on real-time conditions at trip time.

Headlights in Rain

Washington requires headlights whenever wipers are in use — not just at night. Most transplant drivers don't know this. Headlights in rain aren't about seeing — they're about being seen by the driver 300 feet behind you making a following-distance decision.

🌊 A driver who can't see you clearly leaves less gap. Less gap = more phantom jam risk. Your headlights are a phantom jam prevention tool. 💡

Floating Bridge Protocol

The SR 520 and I-90 floating bridges flex and sway slightly in crosswinds — creating hesitation in drivers who feel it for the first time. Maintain speed, stay centered in lane, avoid sudden steering corrections. The bridge is designed for this. Your reaction to it is the phantom jam trigger, not the bridge.

🌊 This is unique to Seattle. No other major US metro has floating bridges on primary commute corridors. New drivers, transplants, and visitors all hit this for the first time on I-90 or 520. Now you know what it is.

Transplant Alert: Texas vs. PNW 🤠→🌲

Texas highways: wide, dry, flat, high-speed. Washington highways: narrow shoulders, wet pavement, steep grades, low-radius curves. The braking distances that work in Texas add 30-40% more stopping distance on wet Seattle pavement. Your instincts from Texas are actively dangerous here in rain.

🌊 WaveGuard sees this in the data: drivers from dry-climate states show 3x more harsh braking events in their first 10 Seattle trips vs. 10 trips later. The adjustment is real and it matters.

It's raining and your wipers are on. Washington law requires you to:

🏗

Module 4 · Construction, E-DUI & Advanced Seattle

I-5 Revive, hands-free law, and the habits that separate flow drivers from the rest

Unlocks at 50 trips

WA Law · E-DUI Act (RCW 46.61.672)

Washington's Electronic DUI law prohibits holding any device while driving — even at a red light, even in stopped traffic. First offense: $136. Second offense within 5 years: $235. The law requires single-touch to activate apps and mandates hands-free operation for all drivers.

🌊 This is why Flow Traffic will always prioritize audio coaching over visual. Looking at your phone to read a coaching tip is exactly what the E-DUI law exists to prevent. Use audio mode.

Construction Zone Law

Washington doubles fines in active construction zones and requires drivers to move over one full lane when passing emergency or work zone vehicles (the Move Over law, RCW 46.61.212). I-5 Revive means you're in a construction zone almost every commute through 2027.

🌊 Construction zones are phantom jam incubators. Reduced lanes + nervous drivers + variable speeds = shockwave paradise. Extra following distance, zero lane changes unless necessary. This is where Flow Score points are won and lost.

Left Lane Law

Washington requires drivers to keep right except when passing (RCW 46.61.100). Continuously cruising the left lane is a traffic infraction. Left lane camping is one of the most consistent phantom jam triggers on I-5 and I-405 — it compresses all traffic into fewer lanes unnecessarily.

🌊 A left lane camper doing 62 mph in a 60 zone forces every faster driver into a single pass, creating repeated merge-and-accelerate events that ripple into shockwaves. Move right. It's the law and it's the physics.

Washington's E-DUI law applies when you're:

Content adapted from Washington State Driver Guide (WA DOL) and Washington State traffic law (RCW/WAC). For informational and coaching purposes only — not a substitute for official driver education or state licensing requirements.
Washington State Driver Guide ↗

Phantom Jam School

Understand the traffic you create

Foundation

What is a phantom jam?

Traffic with no visible cause

One driver on I-405 taps the brakes slightly harder than necessary. The driver behind brakes a little harder. The next, harder still. A shockwave forms and travels backward at 10–20 mph — while traffic moves forward. Drivers half a mile back stop completely with no idea why.

Free flowSlowingBrakingStop-and-go

This accounts for 50%+ of non-recurring congestion in Seattle — not the construction. Human behavior.

Seattle

Why Seattle is different

I-5 Revive and the cascade effect

The I-5 Ship Canal Bridge carries 240,000 vehicles daily — reduced to 2 lanes through 2027. Every displaced vehicle hits I-405, SR 520, I-90, or side streets. One bridge closure cascades across the entire network.

High phantom jam risk zones

Action

Five behaviors that prevent jams

What your Flow Score measures

Speed & Safety

How speed affects everything

Your Safety Score explained

Speeding doesn't just create safety risk — it actively worsens phantom jams and fuel consumption. At highway speeds, every 5 mph over 50 mph reduces fuel economy by 7–14%. On side streets, speed variance is the single biggest phantom jam trigger.

Safety Score is a composite of:

Weather conditions are factored in automatically. Rain, fog, and low visibility increase the safety weight of every braking and speed event — because the same behavior that's borderline in dry conditions becomes genuinely dangerous when roads are wet.

Settings

Flow Seattle

Data & sensors

GPS & Speed

Corridor detection, speed monitoring

Motion sensors

Braking, acceleration, hard braking detection

Collective contribution

Anonymized aggregate data

Drive Smart unlock

Unlocks at 30 trips

Personalized time savings

After 30 trips, Flow Traffic learns your specific corridors, timing patterns, and speed habits to give you personalized departure time recommendations and estimated minutes saved.

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Account

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Flow Traffic never sells your personal data. Trip data is processed on-device. Only anonymized aggregate data is contributed when you opt in.

Flow Traffic Beta · Flow Seattle · v0.3