Using Cell Phone Technology to Collect Travel Data

D. Kyle WardMay 11, 2011

• Intro to Tech and Pilot Program

• Application to MPO Business Model– Congestion Management Process– Travel Demand Modeling

• Pilot Results

• Future of the Technology– Origin-Destination Estimation– Viability vs. Competing Technology

Outline

• Uses cell-tower triangulation to locate cellular devices– Similar to GPS, but less accurate– Ubiquitous cell phone use compared to GPS

• Numerous metrics can be estimated– Speeds– Demographics

Intro to Tech

• Contracted with AirSage– 834 centerline miles of coverage– Significant arterial coverage– 24/7 for March, 2010– Data scrubbed of personal information– Fraction the cost of traditional methods

Speed Pilot

• Congestion Management Process– Yearly data collection program– Before and After Metrics– Congestion Monitoring– Project Identification– Project Programming

Application to MPO

Application to MPO

• Travel Demand Modeling– Validation of Speeds and Travel Time– Volume-Delay Functions

• Accurate Free-Flow Speeds• Speed data matched to counts

Pilot Results

5:30 pm

Pilot Results

4:15 pm

• First signs of slowing– I-40 at Wade Avenue– US 70 between Lynn

and Millbrook

1/6

4:30 pm

• Bottleneck at Wade

2/6

4:45 pm

• Queue backs up along I-40

3/6

5:00 pm

• I-440 begins to slow

• I-40 congestion worsens

4/6

5:15 pm

• US 70 bottlenecks

5/6

5:30 pm

• Delay peaks on all routes

6/6

Pilot Results

• Speed profiles– Peak vs All Day Congestion– Weekend Congestion

• Concerns– Validation of Results?

• Purchase from different vendor/tech

– Default speed data capped at speed limit• Poor posted speed data impacts results• Uncapped speeds prone to outliers

– Solution: establish reference speeds

Pilot Results

• Modeling of Non-Recurring Congestion– 5-minute interval data reporting

• Origin-Destination Estimation– Currently being piloted by the MPO/Airsage– Requires enormous amount of observations

• Currently not possible with GPS

– Estimation of all trips, regardless of purpose

Future Applications

Competing Tech

• Infrastructure-based monitoring– Example: Bluetooth

• Expensive• Limited Coverage

• GPS– More accurate– Less samples (but growing)

• GPS-enabled devices doubling every year?

Questions?

D. Kyle Ward, EI

Transportation Engineer

(919) 996-4395

Kyle.Ward@campo-nc.us