ParkZen uses crowdsourced data collection to access real-time parking data from registered smartphone users. The data are collected from users running the ParkZen app when those users park in or vacate parking spaces within a monitored lot. The data collection occurs seamlessly in the background without the need for users to report their parking activity. ParkZen uses the crowdsourced data to estimate how full a lot is and to report out the lot's occupancy status (Full, Limited, or Available).

There are a total of 73 commuter parking facilities in Northern Virginia; 44 of those lots are part of ParkZen’s scope, although most will not generate up-to-date parking occupancy data until after the trial period. Fredericksburg has a total of 12 parking facilities; 9 of those lots are part of ParkZen’s post-trial period scope.

ParkZen's app uses background location services to detect when users approach and park in monitored lots. Only events confirmed inside a lot's boundary are recorded for occupancy reporting. Users do not need to enter location information into the app. For the automated technology to work correctly, users are asked to enable location services (please set to "always allow" or "all the time"). How personal data are handled is described below.

The app’s success will be measured via independent validation to make sure the technology is working as intended and proving to be effective. The app’s success will also be assessed by reviewing and validating the parking lot usage data for accuracy and timeliness.

The more people at Park and Ride lots who use the app, the more accurate the app data will be.

The pilot lots were chosen by VDOT to provide diversity in lot size, configuration, and proximity to interstates, Express Lanes, and transit.

Park and Ride lots provide motorists the opportunity to park their single-occupancy vehicles at convenient locations and access more sustainable transportation options, such as transit and ride sharing. Reducing the number of single-occupant vehicles on the roadways reduces congestion, improves air quality, and makes commuting better for everyone. Also, ride-sharing has the added advantage of providing commuters with toll-free access to the Express Lanes, offering improved reliability in travel time.

Many motorists appreciate using Park and Ride lots and taking transit or ride-share to complete their trips. However, when traffic is heavy, driving from lot-to-lot in search of empty parking spaces can be unpleasant and time-consuming. Though parking spaces in Park and Ride lots have generally been available in recent years, VDOT has observed an upward trend in Park and Ride usage and expects many lots to start filling up again. The ParkZen app, once fully functional, will allow drivers to identify lots along their routes with available parking. VDOT seeks to provide drivers with essential parking information to assist them in making more sustainable travel choices.

Location and motion data are processed locally on users' phones in the background near monitored lots. Only parking events confirmed inside a monitored lot are shared with ParkZen for occupancy reporting. The occupancy data shared with ParkZen are anonymized on the device before transmission, so individual users cannot be identified from that information. The data fields used to determine parking occupancy are geolocation, timestamps, and motion data. Users who choose to enter ParkZen's monthly giveaway create a profile with an email address. Giveaway information is handled separately from the anonymous occupancy data described above. Creating a profile is voluntary.

ParkZen uses several tools and algorithms to estimate the total occupancy status of a given lot based on information from a subset of users shared through the app. The estimates become more accurate as more people activate the app. Therefore, encouraging additional motorists to use the app will improve its performance. Additionally, VDOT conducts periodic occupancy counts in the Park and Ride lots, which are converted into useful information that ParkZen uses when the app data are inadequate or unavailable.

ParkZen determines parking occupancy using two distinct methodologies: (a) by monitoring users’ smartphone connections to their cars’ Bluetooth, and (b) by processing users’ smartphone motion and activity data to determine when they are entering or exiting parking spaces. ParkZen reports that other regions of the country where the technology has been deployed have seen a 96% success rate in determining available parking spots (VDOT has not independently verified this information). As a part of the preliminary rollout, VDOT is evaluating the solution at specific Park and Ride lots. During the proof-of-concept demonstrations, VDOT will independently evaluate and validate performance of the ParkZen technology.

The app is designed to be energy-efficient by limiting the time it functions in “active” mode. For instance, the app only requests high-location accuracy data for a limited period of time, starting when a user enters a pre-determined parking area (defined as a geofence) and stopping when the user parks, typically within 1-5 minutes. The software is only activated again in the background when a user leaves a parking area. Beta testing has indicated that the average battery drain on an iPhone 12, over a period of 10 days, is less than 1%.