Purchasing a parking permit does not guarantee you a parking spot, and overselling is why.
Although the Purple parking permit is grossly oversold according to the data, Parking Services has observed that the outer Purple perimeter lots are never to capacity. There are on average 500+ spaces open at any given time of any day in the outer perimeter lots, especially in the P-12 Mill St lot.
This observation would imply that overselling of permits is not causing the parking troubles for commuters in the outer Purple lots, and instead the problem may be too many individuals trying to park in the same lots at the same times of day. Individuals who decide to park at further away lots, like the P-12 Mill Street lot, have a higher chance of parking being available.
The Red restricted permit is also oversold by more than 50%, but individuals with Red permits have access to park in any spot on campus excluding reserved spaces.
Similar to the Purple permit, difficulty finding Red restricted parking may be due to too many Red permit holders trying to park in the closest lots at the same time of day, when the chances of parking being available is much higher the farther from central campus an individual parks.
Limited knowledge that Red restricted permits have access to also park in Green and Purple spaces may also cause a cramming of individuals into Red restricted lots when the demand could be spread across all parking lots on campus.
Only 1,607 Red permit holders are not guaranteed a Red restricted spot on a given day. However Red restricted permit holders have access to 6,982 other Green and Purple spaces across campus, greatly increasing their chances of finding a parking space if they divert to parking in a Green or Purple space if they cannot find a Red restricted parking space.
Parking permit overselling is a common practice in the industry. While it may not be popular among the general public, it is fundamentally required for efficient use of parking spaces. Generating the most revenue from each parking space can translate into keeping prices lower for all permit holders.
There is a fine balance between maximizing your spaces and giving permit holders a place to park.
There are a few days when every permit holder will be looking for a parking spot at the same time. People are always away on sick leave, vacations, working from home, have non-traditional working hours, or decide not to drive on certain days. For a campus model, students have variable schedules, exam days, field trips, and staff have sabbaticals.
Most of the time, you could take the list of permit holders for any given lot and put them into clearly defined categories. For a campus example, a lot might accommodate staff, residents, and commuters. Each category of the user has different requirements for the lot. They will inevitably use it at different times and for different lengths of time. Different oversell rates for different permit categories are common (Operations Commander, 2023).