Will current municipal PUDO management survive the robotaxi?

Author: Bern Grush

Date Published: May 4, 2025

Urban curbside space has emerged as one of the most contested resources in modern cities. Today's curbs, primarily managed for parking, loading zones, and transit stops, are the focal point of a complex ecosystem of competing demands. The Pickup/Dropoff (PUDO) challenge—the need to efficiently coordinate vehicles temporarily stopping to load or unload passengers and goods—has evolved from a simple traffic activity into a critical urban management problem that threatens to undermine the promise of next-generation transportation systems, particularly automated vehicles.

The Growing PUDO Crisis

“The curb is an important part of the public right-of-way. It provides a space for vehicles to park on-street; for delivery vehicles (i.e., cargo bikes, cargo vans, and trucks), in particular, it also provides a dedicated space for the loading and unloading of goods close to destinations. Hence it is a key asset for urban freight transportation planning which local governments can administer to support delivery and collection of goods,” note researchers Girón-Valderrama et al. [1]

While curb access is generally regulated, the explosive growth of ride-hailing services, e-commerce deliveries, and food delivery platforms has created unprecedented demand for rapid turnover of temporary vehicle stopping spaces. A typical urban curb that once accommodated a modest number of taxi pickups or deliveries now experiences many more PUDO events, often concentrated during peak periods. In dense urban areas, this leads to double-parking, traffic lane obstructions, circling, and increased congestion—all pressures that will intensify as automated vehicles deploy at scale.

The evidence of current system breakdown is already visible. Girón-Valderrama et al. have also documented that “without an adequate and available supply of loading zones, onstreet and off-street, drivers of commercial vehicles are forced either to spend more time looking for parking or to park in unauthorized spaces. These parking behaviors reduce the capacity of the roadways, causing inconvenience to pedestrians and conflicts with other modes, and ultimately lead to congestion and safety issues.” [1]

The Automated Vehicle Inflection Point

As challenging as the current curbside PUDO situation may be, it represents only a prelude to the far greater coordination problems that will emerge with the widespread deployment of automated vehicles. Several factors make automated vehicle PUDO management particularly complex:

First, the removal of human drivers eliminates the flexibility, judgment, and improvisation that currently helps navigate ambiguous or contested curbside situations. A human driver can make eye contact with other drivers, negotiate access through gestures, or make real-time decisions about alternative stopping locations. Automated vehicles require explicit instructions, algorithms, or permissions.

Second, the economic models of automated fleets incentivize high utilization rates. Without driver labor costs, robotaxis and automated delivery vehicles can operate nearly continuously, each potentially generating more PUDO events than conventional vehicles. Industry projections suggest that major urban areas will see thousands of automated vehicles in operation by 2030, with each generating approximately 50 daily PUDO events. A modest fleet of 1,200 robotaxis implies two million PUDO events in its host city per year.

Third, and perhaps most critically, these automated fleets will be operated by competing companies with no intrinsic motivation to coordinate their activities. Just as Uber does not share its pick-up plans with Lyft, and FedEx does not coordinate its deliveries with UPS, each automated fleet operator will independently optimize its operations without regard for system-wide efficiency unless required to participate in an orchestration framework.

Current Management Approaches and Their Limitations

Cities attempt to address the growing PUDO challenge through various interventions. Physical infrastructure solutions include designated rideshare pickup zones, flexible curb uses that change throughout the day, enhanced loading zones, and signage. Regulatory approaches encompass permitting systems, fee structures, and enforcement mechanisms. Platform-specific solutions have emerged as well, such as ride-hailing companies implementing geofenced pickup points.

These approaches have provided incremental, local, and temporary improvements—and sometimes additional congestion—while falling short of addressing the fundamental coordination problem. Current solutions tend to be reactive rather than proactive, focused on individual rather than comprehensive modes, and lacking the technical infrastructure for real-time orchestration.

Girón-Valderrama et al. “observed unauthorized behavior included double parking, and commercial vehicles parked in PLZs (passenger load zones), bus lanes, tow-away zones, and no-parking zones. Commercial vehicles parking in PLZs (26%) was the largest category of unauthorized commercial vehicle behavior.” [1]

The limitations of current approaches become even more apparent when considering automated vehicle integration. The precision required for automated vehicle operations, the volume of anticipated PUDO events, and the need for machine-readable instructions all point toward the necessity and viability of a digital orchestration system—one that can dynamically allocate curb resources across all managed operators in real-time.

The Multidimensional Nature of the PUDO Challenge

The PUDO challenge represents a complex interplay of spatial, temporal, stakeholder, and scale dimensions, each introducing distinct considerations.

Spatial constraints are defined by the limited curb space in dense urban areas. The typical central business district block face offers approximately 60-80 meters of curb space, much of which is already allocated to competing uses. A 2018 study by the International Transport Forum found that in major cities like Paris, London, and New York, over 80% of curb space was allocated to private vehicle storage (parking), despite this representing one of the least efficient uses of this valuable resource. [2]

Temporal dynamics add another layer of complexity. PUDO activity follows distinct patterns that vary by location, time of day, day of week, and season. How long a vehicle occupies a curb space (‘dwell time’) is a critical factor in determining how many vehicles can use a curb space during a day. Machado-León et al. note: “the dwell time of passenger vehicles picking up/dropping off (PUDO) passengers, including ride-hailing vehicles, taxis, and other cars, is a vital metric for curb management, but little is understood about the key factors that affect it.” [3]

Stakeholder complexity is evident in the diverse ecosystem of participants, each with distinct objectives, constraints, and operational models. Passenger transport operators, goods delivery services, property owners, municipal authorities, and the general public all have different requirements and interests in PUDO management.

Scale problems will emerge as automated vehicles enter urban environments in large numbers. The computational and coordination challenges will exceed current approaches, with daily PUDO activities numbering in the hundreds of thousands daily across entire urban regions.

The Need for Systematic Orchestration

The PUDO challenge bears striking similarities to air traffic control. When multiple aircraft approach an airport simultaneously, they do not negotiate landing order among themselves. Instead, they rely on a central coordination system that optimizes for safety, efficiency, and fairness. Similarly, automated vehicles approaching limited PUDO spaces require systematic orchestration to prevent conflicts, minimize waiting, circling, and congestion, and maximize the utilization of scarce resources.

Just as air traffic control coordinates thousands of flights using standardized protocols and precise timing windows, a PUDO orchestration system would manage the digital 'load plans' of ground vehicles needing curb access.

Machado-León et al. saw early evidence of potential solutions: “Adding PUDO zones, together with geofencing, was found to be related to faster PUDO operations at the curb. A possible way that geofencing technology may help accelerate PUDO events is by providing information shared by driver and passenger about the stop location, which allows them to better prepare before the event.” [3]

This recognition has led to the development of a draft international standard, ISO 25614, to establish a framework for digital PUDO orchestration. This standard defines message formats and multiple transaction flows to enable coordinated access to curb space without requiring competing operators to expose proprietary information.

The Path Forward

To survive the coming robotaxi revolution, municipal PUDO management must evolve dramatically. Cities need to implement digital orchestration systems that can allocate curb space dynamically based on real-time demand and develop regulations for automated vehicle operators to participate in city-wide PUDO coordination. This will require preparing curbs that accommodate the specific needs of automated vehicles while ensuring accessibility, creating flexible governance models that can balance competing stakeholder interests, and investing in digital infrastructure capable of handling the volume and complexity of millions of PUDO events.

The current approach to PUDO management—with its reliance on static allocations, limited enforcement capacity, and siloed operations—cannot serve robotaxis at scale. Only by embracing comprehensive digital orchestration can cities transform this challenge into an opportunity to create more efficient, equitable, and sustainable urban transportation systems.

Just as we would not deploy thousands of aircraft without air traffic control, we cannot realize the full potential of automated vehicles without solving the fundamental coordination problem they present at scale. The transition to automated mobility makes the need to manage curb-access paramount to prevent congestion, maximize passenger and pedestrian safety, maintain service efficacy and equity, reduce enforcement expense, and enable an equitable monetization capability.

What began as a contest for limited curb space is now evolving into a complex orchestration challenge that will impact the future of urban mobility.

Find out more. Register here for URF's May 21 Webinar “Managing Pick-up and Drop-off at the curb,” featuring guests from Austin, San Francisco, and Washington: https://us02web.zoom.us/meeting/register/bozj_tVUTumoSI_h9D4t_Q

Sources:

[1] Girón-Valderrama, G., Machado-León, J., & Goodchild, A. (2019) Commercial Vehicle Parking in Downtown Seattle: Insights on the Battle for the Curb. https://urbanfreightlab.com/wp-content/uploads/2023/04/Commercial-Vehicle-Parking-in-Downtown-Seattle-Insights-on-the-Battle-for-the-Curb.pdf

[2] ITF (2018), “The Shared-Use City: Managing the Curb”, International Transport Forum Policy Papers, No. 56, OECD Publishing, Paris, https://doi.org/10.1787/3af82772-en

[3] Machado-León, J.L., MacKenzie, D. & Goodchild, A. (2023) An Empirical Analysis of Passenger Vehicle Dwell Time and Curb Management Strategies for Ride-Hailing Pick-Up/Drop-Off Operations. Transportation. https://doi.org/10.1007/s11116-023-10380-6