Frequently Asked Questions

Learn how we calculate billboard scores and understand the data.

Scoring Formula

Price Index = (OTS Index + Attention Index) / 2 × Weather Multiplier

price_index = ((ots_index + attention_index) / 2) × weather_multiplier

OTS (Opportunity To See) measures raw impressions, while Attention Index accounts for dwell time. Weather adjusts the final value in real-time.

Traffic metrics are calculated from real-time PeMS highway data:

  • dwell_seconds= visible_distance / (speed_mph × 0.447)
  • OTS= (flow_vph × dwell / 3600) × viewability × occupants
  • attention= OTS × min(dwell_seconds, 10)

Slower traffic = more viewing time = higher score

Visibility is based on billboard physical properties:

  • viewability= 0.0 to 1.0 (how visible is the billboard)
  • visible_distance= meters the billboard is visible (default: 150m)
  • occupants= avg passengers per vehicle (default: 1.5)

Higher visibility and longer viewing distance = higher impressions

Weather Score adjusts value based on current conditions:

Clear/Sunny: 1.0
Cloudy: 0.95
Light Rain: 0.85
Heavy Rain: 0.60
Fog: 0.80
Snow: 0.60

Sheltered locations (bus stops, kiosks) get a 1.2× bonus during rain as people wait under cover.

OTS Index

Opportunity To See - current impressions compared to historical baseline for same day-of-week and hour

Attention Index

OTS adjusted for dwell time and visibility distance - how much attention the billboard actually gets

Price Index

Final Score = ((OTS Index + Attention Index) / 2) × Weather Multiplier - the real-time advertising value

<1.0 Low 1.0-1.5 Normal 1.5-2.0 High >2.0 Premium

General Questions

We use real-time data from the California Department of Transportation's Performance Measurement System (PeMS). This includes traffic flow (vehicles per hour), average speed, and occupancy data from thousands of highway sensors across the Bay Area.

Scores are computed every 5 minutes based on the latest traffic and weather conditions. You can see the “freshness” indicator on the map to know when data was last updated.

Confidence indicates data quality:

  • HIGH - Multiple PeMS stations with recent data
  • MEDIUM - Limited station coverage or slightly older data
  • LOW - No nearby traffic sensors, using baseline estimates

Data Sources: Traffic data from Caltrans PeMS, weather from OpenWeatherMap, billboard inventory from Sim.ai and manual sources.