Title: Inrix Overview
1The Science of Prediction
How Next Generation Traffic Services Will Impact
Business Dr. Oliver Downs, Chief Scientist
Location Intelligence ConferenceApril 4, 2006
2Traffic Congestion Impacts Business
ProductivityFor Urban Areas Traffic Increases
Represent Major Business Hurdle
- During the last decade in the nations 68 largest
urban areas - Time wasted due to traffic rose from 1.9 to 4.5
billion hours - Heavily congested roads increased from 14 to 36
- Congested roads increased from 21 to 28
- Uncongested roads decreased from 65 to 36
- Congestion has real costs and affects business
productivity - Hard costs
- Lost labor time from employees spending hours in
traffic - Extra time for pick-up and delivery/reduced
production time - Extra vehicles to meet just-in-time demands of
customers and scheduling problems caused by
longer delivery times - Soft costs
- Business credibility
3The Evolution
Of Traffic Information
- Traffic Information is evolving to greater levels
of customer value
- Prediction Relevance
- System-wide analysis of traffic
- Useful for planning, re-routing, analysis and
decisions
- Flow Data
- Real-time speed information
- Useful for digital consumption
4What
We Do
Aggregate traffic-related content from public and
private sources
Enhance real-time data using proprietary error
detection and correction. Utilize sophisticated
Bayesian modeling for prediction.
Distribute to customers via XML services
5Traffic Service
Real-Time Flow Prediction
- Features
- Estimates of traffic flow patterns every 15
minutes for up to one year in the future - Amount of time expected for congestion to start
or clear at Inrix Traffic Segments - Drive time predictions for key routes in all
metropolitan markets - Proprietary error detection and correction of
individual real-time traffic sensors
significantly increases the quality of the flow
reporting
Inrix indicates the most likely duration of a
current jammed segment of the highway, making it
easy to calculate route times
Inrix provides the time until the adjacent road
segment will most likely become jammed.
6Bayesian Reasoning
And Prediction
- The Bayesian approach to predictive modeling
allows us to learn the parameters ? of an
appropriate probabilistic generative model from a
set of data,
To do so, we define variables in the model that
correspond to the unknown parameters ?, assign
priors to these variables based on our background
knowledge e and use Bayes' rule to update our
beliefs about these parameters given observed
data
Bayes rule
We can then average over the learned
distributions of ? to make predictions
7Prediction and Forecasting
Leveraging Bayesian Networks
- A Bayesian network is a graphical model that can
be used to uncover causal relationships between
a large number of variables - Inrix utilizes sophisticated Bayesian modeling
incorporating metadata attributes that we
would expect to influence the observed sensor
data both now and some time in the future
- Inrix Metadata
- Current/ Historical Traffic
- Time of Day
- Day of Week
- Weather
- Sporting Events
- Season
- School Schedules
- Holiday Status
- Incident/ Construction Reports
- Express Lane Direction
8Prediction and Forecasting
Rules Underlying the Causal Relationships
- The set of conditionally independent causal
relationships combine to describe a series of
rules that are probabilistically predictive of a
given outcome of the target variables, a decision
tree
- Each end leaf of the tree, describes a particular
rule that a current traffic situation may follow,
and a probability distribution over the predicted
outcome - Color 109 False and Color 118 not False and
Black Start 24 'None' and Pct b15 75 not
'50-75' and Color 132 False and Black Start 144
not 'None' and Color 119 False and Pct b15
132 '30-50
9Bayesian vs. Marginal Models
Why Only Bayesian Models Provide Accurate
Forecasts
- Bayesian modeling incorporating contextual
metadata provides significantly higher
quality/accuracy than simple marginal models
based upon historical traffic
Rolling Stones Concert, 7.30pm at Key Area in
Seattle 10/30/2005. Effect of Bayesian
incorporation of metadata into forecast 48 hours
ahead, for 7pm 10/30/2005.
10Example Customer
Use Cases
- Providing intra day and predicted travel times
and travel speeds for key routes - Delivering time dependent, traffic influenced
routing and dynamic rerouting with turn-by-turn
navigation - Generating 2D and 3D traffic speed maps showing
real-time, predicted forecasted traffic hot
spots
- Illustrating expected times for congestion to
clear - Providing 1-day, 5-day or 10-day metropolitan
traffic forecasts - Analyzing traffic congestion bottlenecks for
transportation and site planning - Highlighting real-time traffic alerts on a map
- Developing highly personalized traffic reports
and SMS alerts
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