Why do some people take the subway in some cities, while other people take the bus or their bike? There are many reasons, but one key reason is station distance: how far do they have to walk to reach the station?
And that goes for any form of transport. Every mode besides your feet is generally several times faster than walking, making people especially sensitive to the walking part of a trip, especially if they’re schlepping cargo or children, or if they have physical disabilities.
City officials in transport have made the same point about bikeshare:
NACTO finds that high station density — approximately 28 stations per square mile — and even station spacing — a station every 1,000 feet — is key…
To increase ridership and system utility, bike share stations should be placed no more than 1,000 feet apart across the entire program area.
A station every 1,000 feet would mean being within 500 feet of the closest station, at most a 2–3 minute walk (given that you walk at 3 mph and are not a crow).
NACTO makes clear that station density is even more important than broad coverage, because station density is key to getting enough riders in a given area to make bikeshare useful for riders and viable for operators — especially with a model where riders pay $100–200 annually for unlimited rides. Broad coverage with typical bikeshare budgets would make for a patchy system with low station density, and thus slower trips.
Personally, I find the joy of bikeshare rapidly diminishes, when you must plan a trek 6+ minutes away to or from a station, especially when it’s for *both* ends of a trip. 10+ minutes walking for a trip that’s only 1–2 miles to begin with, as bikeshare trips usually are, is a pretty miserable outcome, much like if you had to walk 10 minutes from your parking spot at work every day.
Further, NACTO found that “rides increase with station density:”
Another planning research group, the Institute for Transportation Development Policy (ITDP) recommended a usage target of 4–8 trips per bike per day:
Fewer than four daily uses per bike can result in financial unsustainability for the operator (i.e., user fees not able to cover cost to operate each bike), while more than eight daily uses can indicate limited bike availability, especially during peak hours.
What about 🛴?
Despite differences between scooters and bikeshare, the trips they cover are similar — mostly under 2 miles and ~10 minutes, so we shouldn’t expect the optimal guidelines to change much for scooters: there should be enough to have the closest scooter within a ~3 minute walk; a closer vehicle means a faster trip, without the danger that a faster vehicle entails.
More than 8 trips per day may mean there are too few vehicles to meet demand. Until scooter-specific evidence suggests otherwise, a rate of 4–8 trips per day per vehicle is a reasonable target for vehicle utilization.
ITDP mentions a threshold of 4 trips per day as a minimum for making a system viable; operators have previously said vehicles must see three rides per day to be viable. In Austin, Texas, public data puts vehicle utilization rates at 2.6 rides per vehicle per day at best, below the supposed 3 ride threshold of viability.
Why Private Costs Should Matter To Public Officials
Cities have been less concerned about the viability of shared scooters, because they weren’t footing the bill for operations, unlike with bikeshare. And even where bikeshare was unsubsidized (aside from offering free land), as with New York’s Citi Bike, bikeshare operators had little capital; money-losing operations without ongoing government or sponsor subsidy meant the system collapsed and bikeshare disappeared, leaving a big headache for the city.
The deluge of private capital to scooter startups has put aside the concern for system viability among city officials, but the tide is turning. For one, viability is closely linked with sustainability; according to public data, scooters have very short lifespans, typically 100 miles, based on data from Austin, Texas. And firms are increasingly withdrawing from cities large and small, in search of sustainable operations.
Regardless of who supplies the funding, the services need to be financially viable to endure; given the industry’s lack of profits in 2019, current losses of $5–10+ per ride is hardly a blueprint for the future. Making operations more efficient means creating more room for lower prices, better worker wages, better environmental practices, better compliance or some mélange thereof. Some of this can be had through cutting the number of operators, as I previously described.
But a potentially even bigger source of savings is from getting more rides per scooter. In Austin, scooter lifetime mileage was highest when utilization was at its peak — in the summer of 2018, when there were far fewer scooters. And this despite advances in hardware and logistics in the succeeding year and a half.
There are two main elements to maintaining high vehicle utilization: coverage and saturation.
Usage of scooters varies hugely by location:
About 90% of Austin scooter trips originate in ~1% of the area served [8.29 sq mi]. About 95% originate in 2% of the service area [17.19 sq mi] and where ~10% of the population live — John Berry @aniccia
PhD planning student Or Caspi had similar findings, with 95% of trips occurring in 5% of the city area, or in 15 out of 305 square miles.
Evidently, a sliver of the nominal service area accounts for the overwhelming share of rides; a requirement for operators to serve low usage areas, where relatively no rides are happening, ensures that vehicles there will see low usage.
Not surprising then that we continually see operators in Austin, Santa Monica and elsewhere saturating a few dense areas with the bulk of their fleet, aka ‘skimming the cream’. On a per square mile basis, the density of rides in Austin by district is extremely stark (each of ten districts has roughly 10% of Austin’s population).
The pattern of users taking only short (1–2 miles) rides on scooters only compounds the concentration of scooters in select areas, unlike higher speed, seated vehicles like shared e-bikes and e-mopeds, which see roughly triple the average trip distance. In Zurich, high speed e-bikes see far more dispersion than shared scooters.
Which leads to the next point: operators are putting excessive numbers of scooters in those few high-demand areas; it may make narrow sense for a given firm to put out additional scooters to outcompete its rivals, or simply because that one extra marginal scooter will turn a profit. But when each firm makes the same calculation, an excess of vehicles appears. Having yet more and more scooters in an area already saturated with them is not going to make them more sustainable or popular, but just the opposite.
Skimming and splitting the cream among rivals is an improvement over offering scooters where few ride, but it still leads to a lot of waste, through low usage of each vehicle; even if the vehicles were more durable, there would still be the waste of ‘capital’ being used below capacity.
These dynamics strongly resemble what happened when taxis were deregulated in the 1990s, a movement that was reversed when the problems became evident. Specifically, in cities where taxis are located by sight (i.e. hailing or cab-stands), the removal of limits to the number of cabs led to deteriorating service, excess in high demand areas, and lower utilization, among many other negative results.
While there is reason to think unlimited entry is less destructive for corporate sharing services than for independent taxi drivers, unlimited entry still creates waste by slashing utilization without meaningfully enhancing availability, because there are already several vehicles within a close walk. Instead of creating waste, resources can be put towards desirable outcomes like lower prices, better compliance, higher worker wages and greater sustainability.
With taxis, governments have opted to mandate broad coverage. But taxis serve as emergency transport for when a car is needed, particularly for the poor who don’t own cars, so regulating taxis to ensure everyone has some level of access makes more sense; the increased use of small, light vehicles like scooters also stands to improve neighborhoods even when used en masse, while the same can’t be said of cabs flooding a single area.
Lastly, replacing a shared vehicle by buying your own is much more affordable with a scooter or bicycle, than with a car, assuaging the needs for coverage mandates, especially if electric vehicle subsidies are extended from cars to smaller vehicles.
What to make of all this?
We should recognize a series of points:
1. Shared scooters are most useful and popular in a few select areas, especially given the car-centric patterns of most American cities
2. An absence of mandates to cover low-demand areas can markedly increase the viability of operations, by letting operators ‘skim the cream’ and raise utilization to healthy levels, just as bikeshare must do
3. High demand areas if left unregulated, will see excessive numbers of vehicles from operators trying to maximize profits, but collectively squandering them
4. Like NACTO prescribed, there should be enough vehicles in areas served to put one within a ~3 minute walk of prospective riders during peak times, but there are rapidly diminishing returns, as more vehicles means more waste without significantly increased service availability.
What would implementation look like?
Santa Monica, the city where it all began, decided to only allow more scooters if operators saw usage greater than 4 rides per day per vehicle, a threshold that may coincide with financial viability; only 2 of 4 operators, Lyft and Uber have seen usage higher than this threshold, and perhaps only in a seasonal peak, the month of June. (Plus, Lyft and possibly Uber have since raised their prices, cutting demand.)
Officials can go further, and cut existing fleet allowances until rides per day are between 4 and 8 times the number of vehicles available daily, across all operators.
In Austin, with ~14,000 rides daily in 2019, that would equate to 1,700–3,500 vehicles per day, compared with the ~5,000 observed daily in 2019. If rides were limited to the 5% of city area where 95% of rides occur, that would amount to ~330 vehicles per square mile; while operators already reduce deployments during winter, demand drops even more, so utilization reached below ~2.2 in December 2019.
Operators would still be free to field vehicles beyond core areas, provided their collective fleets met the utilization threshold of 4+ rides per vehicle daily. Requiring say, 5 or 6 rides per vehicle daily creates more value to put towards other public interests, but it comes at the expense of reduced geographic coverage, a tradeoff that each city must strike.
Why high utilization is good
When utilization goes up, so goes lifetime mileage per vehicle, evidence suggests. The carbon emissions involved in making the scooter gets spread over more vehicle miles; operators spend less time and gas traversing the city to service scooters now occupying a smaller area. And ultimately, cost savings allow room for price cuts, via competition (in the street or through exclusive city contracting), which fuels adoption, kicking off a virtuous cycle of lower costs, less ecological impact, lower prices, greater availability and higher usage. Cities may leverage some of these savings into better wages for workers or higher vehicle disposal standards, without raising consumer prices, leaving operators with only modest profits.
Lower prices also encourage more frequent use, which should help reduce crash rates, which appear highest for new riders; there are also many low income riders that are technically eligible for reduced fares, but never get them — either because they don’t take many rides (users average 1–2 rides per month), because operators make it difficult to get discounts, or because the low income riders aren’t already receiving government aid that is required by operators as proof of eligibility for aid. Lower prices for everyone would reduce the amount low income riders pay per ride, and existing aid programs could be kept in place.
Coverage: Small and Dense, not Broad and Sparse
The ease of using one transport mode vs another varies almost infinitely, not only across cities but within each one. American cities may have long stretches of land hostile to everything but driving, and then little oases where anything and everything else may flourish. Between their short trips, tender frames and need for safe passage, shared scooters are particularly dependent on these oases to thrive; mandating they cover much of American cities would stifle their potential to become a popular and safe, low cost, low impact choice by stretching them thin.
The transport researchers Davids Levinson and King write that instead of looking at transport from a regional perspective and increasing transit use from say 1.5% to 3%, we ought to look for routes where public transit can dominate, and take mode share from 40% to 60%, 80% and beyond. “Otherwise, the service is spread out like peanut butter and does nothing well.” The same tack should be taken with shared scooters, in combination with walking, biking and transit — a focus on those parts of a city where solo drivers can definitively be pushed to the margins, or banned outright. Cities can change quickly with ‘oases of excellence’ instead of a layer of thin gruel for all. Shared bikes and scooters, alongside the essential steps of abolishing parking requirements, housing near jobs and dedicated transit lanes, can make banning cars in city centers that much easier.
Seattle, the American city known for its uniquely increasing use of transit, has also deliberately removed parking requirements and concentrated new homes in these oases, which it calls urban villages. Rather than trying to fix a whole city through heroic effort and saddle those urban villages with the burden of gilding the surrounding sprawl… We should let these oases flourish, and let more people live by them.
