Raw signal
Phones record acceleration on the vertical axis roughly 5 times per second during Uber trips.
infrastructure
costs
inequality
Every pothole has a price. One study computed it to the cent.
Every time a car jolts over broken asphalt, the driver pays: in time, in discomfort, in wear on the vehicle. An NBER study turned the accelerometers in Uber drivers' phones into the largest road sensor ever built and put a price on every mile of rough road. The conclusions can be checked figure by figure: bad local roads slow traffic, cost at least 31 cents per mile, and cluster in lower-income cities and neighborhoods.
Source: NBER Working Paper No. 31981, December 2023. Working paper circulated for discussion, peer review not completed.
5M+
urban road segments measured in the US
$0.31
per mile, conservative estimate for the median local road
$318
annual gap, at 3,000 local miles, between a 100% Black and a 100% White neighborhood
1,449
locality border pairs underpinning the cost estimate
What your road costs you, per year
Pick a scenario and drag the mileage. The figures come straight from the study: 31 cents per mile driven for the median local road, 23 extra cents for one standard deviation of roughness, 10.6 cents for the neighborhood contrast reported in Table 9.
At 3,000 local miles per year (4,800 km), the median local road costs you this much versus a perfectly smooth one.
$930
$0.31/mi
3,000
≈ 4,800 km
Formula: annual cost = local miles × cost per mile. The study uses 3,000 local miles for the $318 example.
Over 10 years, at the same mileage: $9,300.
How the phone became a road sensor
The researchers used the vertical acceleration recorded by Uber drivers' phones, then separated driving style from the physical quality of the asphalt. Validation came from official indices, railroad crossings, and Chicago resurfacing records.
Standardization
For each segment, roughness is predicted at a fixed speed, so the measurement reflects the road rather than the driver.
Validation
Correlation with the official IRI index: 0.5-0.7 on highways, 0.7 on arterials. Segments with railroad crossings come out, predictably, much rougher.
Pricing
Cost is inferred from the speeds drivers freely choose when crossing locality borders or entering freshly resurfaced stretches.
A rough road slows you down and taxes you
At a time value of $15 per hour, the total cost of roughness comes out 43% above the pure time loss. The difference is discomfort and wear: suspension, tires, everything the car absorbs instead of the asphalt.
The figure used throughout this page is the cautious one: 31 cents per mile for the median local road. The alternative estimate, computed from Chicago resurfacing, would have come out double. The study reports it but keeps the locality-border version.
Bad infrastructure is unevenly distributed
Across the 100 largest US metro areas, local roads are rougher where incomes are lower. The gap shows up mostly between localities: they own most local roads and have very different tax bases.
Table 9 puts a number on it: moving from a 100% White to a 100% Black neighborhood means 10.6 extra cents per mile. At 3,000 local miles per year, the gap reaches $318.
The dominant share of the racial gap appears between localities. A smaller component persists even between neighborhoods run by the same authority.
Repairs rarely reach the worst roads
The study compares roughness measured in August 2021 with subsequent resurfacing in New York, Dallas, Columbus, and Portland. Only New York shows a link, and a modest one, between how bad a road is and its chance of getting fixed.
New York: a small but measurable weight
Repair decisions are consistent with a weight of just 10-12% placed on the roughness-plus-traffic criterion.
Three cities, no pattern
In Dallas, Columbus, and Portland, no statistical link appears between road roughness and the resurfacing rate.
Repairs fall behind
Of 101 localities surveyed nationally, 62% say they resurface under 30% of the roads that need it.
Other criteria come first
48% of localities name scheduled utility work as a factor in resurfacing prioritization.
The public question
If roughness can be measured at segment level, the criterion "worst roads first" becomes testable. Any city can compare its actual resurfacing list against a list ordered by the cost borne by drivers.
Budgets, utility work, safety, and political balance remain separate decisions. The test still puts a shared unit on the table: dollars per local mile, paid by the people who drive there.
The method travels. Any city with ride-sharing traffic, Bucharest included, is already generating the raw data. What's missing is the will to turn it into a public priority list.
Sources
Every figure on this page comes from the primary study and the tables indicated below. The editorial terms "annual cost" and "median local road" follow the formulas in Section 4 of the study.
Lindsey Currier, Edward L. Glaeser, Gabriel E. Kreindler, "Infrastructure Inequality: Who Pays the Cost of Road Roughness?", NBER Working Paper No. 31981, December 2023
References used: abstract; Sections 1, 4, 5, 6, and 7; Figures 8-14; Tables 6, 7, 9, 12, 13, 15, and 16.
Data appendix pentru NBER Working Paper No. 31981
The appendix is indicated by the authors as the source for data construction, coverage, and additional procedures.
Working paper
NBER states that working papers circulate for discussion and comment and have not gone through the peer review applied to official NBER publications.