Alan. R.P. Journet Ph.D.
Southern Oregon Climate Action Now
Facilitator SOCAN Medford Climate Action Team
7113 Griffin Lane
Members of Medford City Council
Members of Medford Planning Commission
Matt Brinkley, Director of Medford Planning Department
Reference: Minimum Parking Requirements
I write as cofacilitator of Southern Oregon Climate Action Now (SOCAN https://socan.eco) and facilitator of SOCAN’s Medford Climate Action Team in relation to city consideration of Minimum Parking Requirements (MPRs). Initially, I was relatively uninformed about this issue but have undertaken some research into the Planning literature and engaged in a little reflection. I offer the following thoughts.
Economic Considerations and Current Trends:
My most interesting discovery was that, according to Shoup (1999) it is unclear how the concept of Minimum Parking Requirements entered the Planning arena, and additionally, because theory and data play such a small role in determining which specific MPRs will be applied in any given situation, the requirements ultimately imposed often appear foolish. This author also argues that MPRs inflate trip generation rates and that a better alternative would be to allow pricing (i.e., the free market) to do the planning.
Quednau (2018) identified three arguments against the principle of MPRs:
- From a financial perspective, they undermine financial productivity and prosperity.
- They serve as a problem for small business owners, homeowners, developers and renters.
- A result of MPRs is that cities become encumbered by empty space that is inadequately used.
Quednau (2018) exemplified the last item by noting that if one enters a city on Black Friday, the day when one would expect the maximum number of parking spaces to be needed, there remain abundant spaces unoccupied.
Spivak (2022) discussed the benefits to eliminate MPRs and illustrated this with an example of how an Olive Garden management team in Auburn, Maine was prevented from buying and expanding a Ruby Tuesday’s site when MPRs were in place because they would have had to generate more parking spaces. However, when the MPRs were removed, they were able simply to buy the site and expand into a current parking lot and thus open for business without being thwarted by issues related to lack of parking. In discussing the elimination of MPRs, Spivak (2022) offered the summary that: “In the smallest of towns and the biggest of cities, these new zoning reform policies that abridge MPR help boost small businesses, promote housing development, and put people over parking.”
In discussing ‘The Pseudoscience of Parking Requirements.,’ Shoup (2020) suggested that cities:
- Remove off-street parking requirements. This would allow developers and businesses to decide the number of parking spaces they should provide to customers.
- Charge the right prices for on-street parking. The suggested criterion is the lowest prices that would leave one or two vacant spaces on each block. This ensures there will be no parking shortages. Thus, supply and demand control the price to be charged.
- Spend the income from parking fees to improve public services on the metered streets since the use of the funds to improve on-street parking will make the policy more popular.
The evidence that I encountered suggests that Minimum Parking Requirements are of questionable value and that residents and the local economy would be better served if these requirements were eliminated completely. It is argued that the free market should be allowed to determine how many parking spaces will be required for any given structure.
In discussing the impact of Minimum Parking Requirements on affordable housing, Lehe (2018) indicated that MPRs (1) on average add $200 to rental housing because the cost of parking is bundled with the residence itself. Meanwhile the cost of a condo is elevated by $43,000 for the same reason, and (2) encourage larger units rather than relatively small units. Clearly, these outcomes contribute to the unavailability of affordable housing for low-income residents; they do not solve the housing crisis.
As identified in the Medford Climate Change Adaptation and Resilience Plan (CCARP, 2024), one of the compounding influences exacerbating the global warming impact on Medford is that this city, like others, is an Urban Heat Island which means that the city experiences summer temperature substantially greater than the surrounding rural area. Yale (2018) reported that “urban centers can be an average of 5 degrees hotter than the surrounding rural areas.” This phenomenon occurs because incoming solar radiation, mainly that in the shorter visible light range, contacts the concrete and tarmac and is converted into longer wavelength heat energy. Thus, these surfaces can heat to temperatures far greater than the local atmosphere. The absorbed heat is then radiated back into the atmosphere warming the city. This is the reason that solar ovens are so effective, and our cars can become unbearably hot when left in the sun. Light wavelengths pass through the windows substantially undiminished but heat wavelengths do not pass out anywhere near as effectively; thus, the solar oven and our cars heat up.
Unsurprisingly, infrastructure is the leading contributor to the Urban Heat Island Effect, especially roofs and parking lots (Yale 2018). Roofs, conceivably, could be painted lighter colors to reflect the incoming solar radiation, but this solution would potentially be blinding if applied to parking lots. It is also noteworthy that, as CCARP (2024) indicates, “People of color and low-income households are particularly vulnerable to the urban heat island effects….” The presence of vast expanses of little used parking lots thus contributes to the suffering of all residents and also imposes a measure of social injustice.
Stormwater run-off is an additional concern about the negative contribution of parking lots to cities. In rural regions, rainwater generally is absorbed by the soil and contributes to the productivity of the natural or agricultural communities. Stormwater in rural regions may cause flooding but does not contribute pollution to natural waters when it ultimately flows into creeks and rivers. Urban rainfall, however, fails to penetrate the ground because buildings, roads and parking lots constitute a barrier. This water simply flows into storm drains and ditches and thence either into the community wastewater treatment plant, potentially overloading the system, or, as in Medford, into neighboring creeks and thence rivers. If this water were moderate in volume and unpolluted, these would not necessarily be problematic outcomes. However, stormwater flowing from parking lots is generally polluted. As Waters et al. (2011) noted several years ago: urban run-off encounters debris and pollutants such as fertilizers and pesticides, pet waste, leaky car toxins, etc. as it flows through the urban environment. Greentumble (2016) also pointed out that parking lots are especially likely to contribute oil, grease, heavy metals and sediment. Indeed, EPA (2003) long ago identified a long list of pollutants from urbanization, pointing out that “These pollutants can harm fish and wildlife populations, kill native vegetation, foul drinking water supplies, and make recreational areas unsafe and unpleasant.”
In considering overall transportation policy ITDP (2022) argues that cities need to rethink parking. They particularly argue that “This history of parking minimums has ultimately driven down the cost of parking in many cities by providing an excess of free and low-cost parking space, compelling drivers to take more trips by car (even unnecessarily) with the assumption that there will always be a place to park.” They also note that: “the provision of expansive and low-cost parking serves to induce more driving and unsustainable uses of urban space…” and “parking space and storage also tend to be composed of unsustainable, resource-intensive, and non-porous materials (asphalt, concrete, gravel, etc.) that contribute to urban heat island effects and compound stormwater pollution and runoff.”
In terms of our collective contribution to the climate crisis, it’s important to acknowledge that the assessment of total greenhouse gas emissions from automobile use, whether the vehicle is powered by electric, internal combustion engine, or is a hybrid, should include emissions that result from the construction and maintenance of parking structures used by the automobile. Chester et al. (2010) assessed this several years ago and concluded that parking construction emissions: “constitute a significant portion of an automobile’s life-cycle emissions, ultimately increasing the total cost of driving.” This increased cost is not borne by the driver but is externalized to the community since the community as a whole builds and maintains the parking lots through taxes. This is exactly an example of what ‘externalizing costs’ means: the individual reaping the rewards (i.e., the driver) benefits, while others (i.e., community taxpayers) incur the cost.
As I researched this topic, I included a search for ‘arguments in favor of Minimum Parking Requirements.’ Curiously, I found most of the hits actually either argued against MRPs or that MRPs are ‘a thing of the past.’ It is also worth noting that the Planning literature seems to focus purely on economic issues and undervalues the environmental costs and benefits of the options discussed.
The evidence suggests to me that Minimum Parking Requirements increase the required number of parking spaces well beyond that which is necessary, even on peak use occasions, cause economic harm to businesses, and simultaneously exacerbate the urban heat island effect and water pollution impacts of urban areas. Furthermore, if the city of Medford is serious about addressing the local housing crisis, it seems that removing MRPs would serve it well. MPRs also, evidently, increase the life cycle pollution emissions assessed for automobile travel.
I understand that some individuals are inclined a priori to be skeptical about repealing Minimum Parking Requirement rules in Medford for reasons seemingly unrelated to their value, but my reading of the evidence suggests abandoning MRPs would constitute a win-win-win-win action:
- it would benefit the economy while promoting a free market solution to parking questions,
- it would reduce the heat island effect thus benefitting all residents especially the more vulnerable,
- consistent with the CCARP, it would contribute to the city’s commitment to undertaking steps that promote climate adaptation and resilience, and
- it would reduce the rental and purchase price of new low-cost housing developments and thereby potentially put downward pressure on the rent and price of existing housing.
CCARP 2024 Climate Adaptation and Resilience Plan: Vulnerabilities. City of Medford Planning Department. https://www.medfordoregon.gov/files/assets/public/v/1/planning/documents/long-range/ccarp_final_122023.pdf
Chester M, Horvath A, Madanat S. 2010. Parking infrastructure: Energy, emissions, and automobile life-cycle environmental accounting. Environmental Research Letters 5 (3): 034001. https://iopscience.iop.org/article/10.1088/1748-9326/5/3/034001/meta
EPA 2003 Protecting Water Quality from Urban Run-off. United States Environmental Protection Agency https://www3.epa.gov/npdes/pubs/nps_urban-facts_final.pdf
Greentumble 2016 Environmental Problems with Parking Lots. Greentumble https://greentumble.com/environmental-problems-with-parking-lots
ITDP 2022 To Tackle Climate Change, Cities Need to Rethink Parking. Institution for Transportation and Development Policy. https://www.itdp.org/2022/09/20/to-tackle-climate-change-cities-need-to-rethink-parking/
Lehe L 2018 Minimum parking requirements and housing affordability. The Journal of Transport and Land Use 11 (1): 1309-1321. https://www.jtlu.org/index.php/jtlu/article/view/1340.
Quednau R. 2018 3 Major Problems with Parking Minimums. Strong Towns https://www.strongtowns.org/journal/2018/7/2/3-major-problems-with-parking-minimums
Shoup D. 1999 The trouble with minimum parking requirements. Transportation Research Part A; Policy and Practice. Science Direct https://www.sciencedirect.com/science/article/abs/pii/S0965856499000075#:~:text=This%20foolishness%20is%20a%20serious,of%20not%20considering%20this%20cost
Shoup D. 2020 The Pseudoscience of Parking Requirements. Practice Parking Reform. Zoning Practice. https://parkingreform.org/wp-content/uploads/2023/03/APA_-Practice_Parking_Reform_February-2020.pdf
Spivak J. 2022 A Business Case for Dropping Parking Minimums. American Planning Association https://www.planning.org/planning/2022/spring/a-business-case-for-dropping-parking-minimums/
Waters S, Farrell-Poe K, Wagner K. 2011. When it Rains it Runs Off: Runoff and Urbanized Areas in Arizona. Arizona Cooperative Extension. https://extension.arizona.edu/sites/extension.arizona.edu/files/pubs/az1542.pdf
Yale K. 2018 Heat Island Effect: What You Need to Know. Buildings. https://www.buildings.com/building-systems-om/roofing/article/10186046/heat-island-effect-what-you-need-to-know