Week 1 — What Level Is Your Curb?

There is a Bortle scale for night skies, a Saffir-Simpson scale for hurricanes, and a Kardashev scale for civilizations. Each describes a phenomenon as a small set of clearly-defined levels, with criteria that any observer can apply. None of them are exact. All of them are useful, because they let us compare across cases and talk about progress.

There is no such scale for the curb. There is no shared vocabulary that tells a city how its curb stacks up against its peers, where it sits on a developmental arc, or what graduating to the next level would actually require. Without one, every conversation about parking technology turns into a feature checklist and an RFP. Cities buy hardware that looks impressive, deploy it incompletely, and end up with results no one can really compare.

It’s time to fix that. We propose a simple framework: the Curb Productivity Scale (CPS) — a five-level classification, Type 0 through Type IV, defined across six dimensions. A city’s level on the scale is the level of its weakest dimension.

The Curb Productivity Scale at a glance

Two design rules keep the scale honest. The first: a city’s level is the minimum of its dimension scores. Demand-responsive pricing without dynamic signage is a billing trick — it doesn’t move you up, because the driver can’t act on what the algorithm decided. The second: levels are observable from the curb. A driver standing at a space should be able to tell what level the city is at by what is or isn’t on the sign, the meter, the app, and the wayfinding signage at the corridor entrance.

Most American cities sit at Type I or Type II. The cities held up as exemplars — SFpark in San Francisco, LA Express Park, Seattle’s paid corridors, Pittsburgh — lead the field on the Policy dimension with demand-responsive pricing on flagship corridors. But the other five dimensions trail. SFpark and LA Express Park both decommissioned their per-space pavement sensors years ago and now infer occupancy from transaction data. Decision Point Info remains a smart meter showing rate, not dynamic per-space indicators with live limits. Enforcement is officer-driven with handheld assist, not LPR-based exception dispatch. Under the minimum-of-dimensions rule, even the exemplars operate at Type II overall — Type III policy on a Type II foundation. No city is at Type IV today, and arguably no city is fully at Type III either.

The gap between Type II and Type III, on a mid-size downtown, is worth $50–$90 million a year in foregone commerce. That’s not a procurement decision. That’s a strategic-planning decision.

Over the next six weeks we’ll work through the scale level by level — what each Type looks like on every dimension, where most cities sit, and what investments graduate them up. The closing post in week 8 brings the dimensions back together — the economics of advancing one level overall and the order in which cities should sequence the investments.

The first step is knowing where you are.

Next week: Type 0 — the Wild Curb. What it looks like, where it still exists, and why even cities that think they’ve left it behind often haven’t.