Eli Goldberg


URBS 400


Do Segway HTs Belong on San Francisco Sidewalks?


(Author’s disclaimer: I’m not a professional transportation analyst or urban planner. I researched and wrote this entire paper in a 24 hour period for Carol Silverman’s undergraduate “Dynamics of the American Cities” summer class, where it received an A. I’ve been following the Segway since the first “Ginger” rumors, and wrote the paper to enjoy the opportunity to critically assess the product separate from the widescale media hype.)


“After a year of speculation, inventor Dean Kamen unveiled his mysterious “IT”, which is a battery-powered two-wheel people mover. Many believe it will completely revolutionize the way people get hit by cars.”

—- Saturday Night Live
     April 27, 2002




            On December 2nd 2001, Dean Kamen unveiled the much-speculated “IT”, now known as the Segway Human Transporter (Segway HT), a “a self-balancing, personal transportation device…designed to operate in any pedestrian environment.”


Coverage of the announcement spanned nearly every general American news source. Time Magazine described it as “the most eagerly awaited and wildly, if inadvertently, hyped high-tech product since the Apple Macintosh”.[1]


            Steve Jobs was widely quoted as saying that people will erect entire cities around “IT”. Legendary venture capitalist John Doerr injected his largest-ever single investment into the company ($38 million), and publicly predicted that Segway will be the fastest company in history to attain $1 billion in sales.[2] 


            But perhaps most unusual was Segway’s utopian and environmentalist overtones in describing the device’s potential to rid cars from cities’ inner cores. With inventor Dean Kamen’s oft-recounted history of revolutionary medical inventions to aid and empower the infirm and disabled, spectators were primed with similarly revolutionary expectations for the Segway HT.


Unlike their now-perished dot.com business predecessors, Segway didn’t invent the HT in order to merely make money — they’re openly on a mission to free global cities from the choking dominance of automobiles. “If all we end up with are a few billion-dollar niche markets, that would be a disappointment. It’s not like our goal was just to put the golf-cart industry out of business.”[3]


            Segway ultimately seeks “a reconfiguration of the way communities are built by significantly extending people’s walking zones”[4], ostensibly enabled by the Segway HT.


            Before the Segway HT could begin to supplant the automobile, cities must permit its use on the only transit pathways that the common citizen would risk without several tons of protective automobile armor: the sidewalk.


However, sidewalks are currently protected from existing motorized vehicles, due to their real or perceived risks to pedestrians. To operate the Segway HT legally in a pedestrian environment, regional and state governments must add special exemptions for the Segway, as a “personal electric mobility device”.


Raising the eyebrows of pedestrian advocacy organizations such as AmericaWalks, Segway’s lobbyists have blitzed state and metropolitan governments around the nation — and in the span of six months successfully received these exemptions in approximately 20 states.[5]


Among the states that have approved the Segway HT:


• only two states currently appear to require some form of license, operator training, or safety warning.


• only a single state — Georgia — currently appears to require that adult Segway operators wear a helmet.


            In this paper, we will examine both sides of the debate of whether the Segway HT is suitable for city sidewalk usage. In the belief that some degree of added pedestrian risk may be an acceptable tradeoff to substantially mitigate pedestrian-hazardous automobile usage, we will also briefly assess Segway’s claims of their product’s ability to displace the automobile for in-city trips.



Safety risks for pedestrians and Segway riders


“[Segway HT] is no different than a fast-walking person, and does not pose the threat to pedestrians that skateboards, bicycles or in-line skates do.”

— Gary Bridge

    Vice President of Segway LLC

    March 19, 2002


            Pedestrian, elderly, and child safety advocates haven’t been pleased by the prospect of sharing sidewalks with motor vehicles weighing up to 420 pounds, legally hurtling by at speeds of up to 20 miles per hour.[6] (Although initial Segway models are limited to 10-12.5 miles per hour, legislation permitting their usage typically allows speeds of up to 20 miles per hour.)


            Segway’s responses to these concerns have largely described the product’s engineering redundancy and safety affordances, outside of likely operating risks from real-world interactions with other pedestrians and motorists. Indeed, Segway consistently positions and describes the device as an extension of the traditionally safe activity of walking, referring to Segway users as “empowered pedestrians”.[7]


Segway appears to believe that a “safe” design is one that is operationally redundant and highly maneuverable, and that the Segway HT is an inherently safe vehicle by design. As this section’s header quote suggests, they appear to believe the risks surrounding existing medium-speed transit devices such as bicycles and scooters do not apply to the Segway.


The consumer model product specification explains, “Safety is our top priority in both design and operation…If any system begins operating at diminished capacity, the other is programmed to assume responsibility all the while maintaining balance while Segway HT slows down to quickly and safely shut down.”


Their media statements have largely comprised soundbites lacking in sufficient substance to seriously critique. In such a soundbite, Dean Kamen explains, “Our machine is compatible with the sidewalk. If a Segway hits you, it’s like being hit by another pedestrian.”


The company has not published any formal safety test results supporting their argument that Segway HTs indeed warrant special exemptions to existing motor scooter restrictions.


In response to an inquiry for such results from Dr. Gary Smith (Director of the Center for Injury Research and Policy at Columbus Children’s Hospital) Matthew Dailida of Segway on April 23, 2002 that “Data… (are) in developmental stages and (are) unavailable (for) public consumption.”[8]


            Segway’s response to a request for quantitative safety data for this paper comprised a form letter explaining that “Segway is currently in the process of developing a segment for our website that will benefit students and educators on learning more about the technology and concepts that inspired the Segway HT invention.


            Pedestrian advocacy groups tend to look at the Segway HT in terms of existing motorized scooters that have been banned from sidewalks, rather than as an “extension of walking”. They fear it’s a gizmo that will provide preferential sidewalk access to the wealthy, and presents many of the same pedestrian dangers that necessitated their predecessors’ banishment from sidewalks. They’re skeptical that any amount of ingenuous design could sufficiently mitigate safety threats inherent from operating a higher-speed motorized vehicle in a pedestrian right-of-way, and which inevitably intersects with motor vehicle traffic.


Walk San Francisco would like to see “studies show[ing] that the Segway devices are inherently safe and compatible with pedestrians on sidewalks in a San Francisco-style dense urban setting.”[9] before considering supporting its operation on San Francisco sidewalks.


            They point out that no matter what technology the scooter contains, it’s limited by the reaction time of the human rider operating it: “The National Safety Council has determined that the average reaction time for an emergency braking situation is three-quarters of a second. At even 12 mph, a Segway would therefore travel an average of 13 feet before the user would even initiate braking. Segway claims that the device could then be stopped in an additional 5 feet (which would be a remarkable 1g of deceleration if true) for a total stopping distance of 18 feet. Again, this would be completely unsafe for sidewalk use.”[10]


Dr. Gary Smith shares this skepticism that technology can overcome innate human limitations. “Although the Segway has internal gyroscopes for stability, the driver of the device does not. And unlike other motor vehicles, the driver of the Segway is standing unrestrained, not sitting. The operator’s high center of gravity is likely to pull him/her off of the scooter in a quick turn.”


            In public demonstrations, Segway representatives proudly demonstrate the product’s safety by running over a person’s foot or hand, and pointing out how the device shifted its weight to the other wheel, inferring near-magical safety properties.


            However, as Dr. Gary Smith points out in his testimony against permitting Segway HTs to operate virtually unregulated on Ohio sidewalks, “Segway representatives demonstrate a Segway riding over the top of a person’s hand without injury; however, this is irrelevant to the real injury hazard of the device colliding head-on into a pedestrian… A collision is inevitable and the laws of physics will prevail, and potentially, a significant energy transfer will occur to the pedestrian and

also to the operator, resulting in injury.”[11]


            Ironically, for a device premised on advanced gyroscopic stabilization technology, Walk San Francisco shares skepticism based on simple Newtonian physics that being hit by a Segway is like “being hit by another pedestrian”. They explain, “Energy increases with the square of velocity. This means the energy expended in a crash of a rider on a 80 lb Segway scooter going 12 mph would be approximately 25 times greater than for a person walking.”


            Indeed, confirming the fears of Dr. Smith and pedestrian advocacy groups, the first Segway injury occurred on May 2nd, 2002 in an Atlanta trial of the device, when the operator hit a “protrusion in the sidewalk”. The operator landed in the hospital with a minor knee injury.[12]


            Consistent with Segway’s usage of pedestrian metaphors to describe the Segway HT, the company’s marketing director Tobe Cohen responded that “Our feet are very intuitive, but sometimes we still trip up.”


            But, do pedestrians necessarily end up wheeled off to the hospital from tripping on the sidewalk?


Segway’s self-portrayal


            The hazards feared by advocacy groups don’t surface in Segway’s promotional videos. Instead, Segway consistently demonstrates the product’s usage in relatively idealized suburban and exurban environments, rather than the real-world city streets which the device is intended.


The outdoor scenes of their “Segway in General, Everyday Use” video largely take place on narrow, straight, intersection-free streets or paths uninhabited by cars or more than a handful of pedestrians.


In other promotional segments where pedestrians appear, they appear to be already aware that a Segway HT user is coming, despite the scooter’s silent operation. The Segway operators also uniformly slow down to pedestrian speeds upon approaching a walker, a form of etiquette that existing scooter users do not necessarily engage in. No children or senior citizens were apparent in any of these videos — only maneuverable, able-bodied adults.


Although the promotional video exclusively shows the Segway HT operated outdoors in exurban and park-like settings — never on already-crowded city streets — the video’s narrator nonetheless asserts, “What Henry Ford did in the last century for rural America is what this device will do in the next century for city-dwellers all over the country and all over the planet.”[13] (The narrator carefully avoids the subject of what Henry Ford did for urban America!)


            It ends with a suited pair of briefcase-carrying people entering their familiar client’s exurban cul-de-sac home, picking up glossy promotional materials, and placing them in their briefcases.


But, like so much else surrounding the Segway HT, it leaves unanswered the broader context necessary to construct a truly realistic use case. Did they come from an office center? If so, why would they choose to travel through exurban streets on a transit mode that constrains them to a fraction of the speed and distance of an automobile? More importantly, it leaves unanswered how they traveled equally effortlessly through the prerequisite pedestrian-unfriendly arterial streets that usually connect suburban and exurban developments.


            None of the videos demonstrate the Segway HT’s operation at night, or in any climates but summer sunshine. A separate “Segway HT in Snow and Ice Applications” video exclusively shows the Segway HT operated in a rural field, not in the hazards of a real-world winter city.


Nor does Segway’s website show the Segway HT in transportation scenarios encompassing a full range of real-world urban interactions. In nearly every photo of the Segway HT in outdoor uses, the device is entirely stationary — holding a operator who is cheerfully observing the scenery, or interacting with another bystander. None of these scenarios depict moving automobiles or inattentive pedestrians gabbing on cell phones.


Especially if the Segway indeed diminishes the use value of public sidewalks to pedestrians, its introduction raises privatization and social equity issues. Is it just to amend laws to allow on sidewalks a $3,000 device affordable only to upper-class individuals, exclusively controlled by a single for-profit vendor?


The automobile was once hailed as a utopian “magic carpet” to liberate humanity; it instead holds American city streets captive from most all other users but other motor vehicles.


Dean Kamen now describes the Segway as being like a pair of “magic sneakers”[14]. It would be fittingly tragic if the Segway achieves unintended ruinous results on sidewalks equal to what the automobile has achieved on the streets.  



Segways and the reduction of automobile dependence


“Most people in the developing world can’t afford cars, and if they could, it would be a complete disaster. If you were building one of the new cities of China, would you do it the way we have? Wouldn’t it make more sense to build a mass-transit system around the city and leave the central couple of square miles for pedestrians only?”

— Dean Kamen

    December 2nd, 2001


            The pay-off touted by Segway for permitting Segway HTs on sidewalks is the ability to reduce or eliminate automobile dependency, by shifting in-city trips from an automobile to a Segway HT.


            Although AmericaWalks’s formal position on the Segway is that “Nothing that moves faster than walking speed belongs in the space intended for walking”, they acknowledge its potential benefits. “Any car trip that is replaced by another mode benefits bicyclists and pedestrians.”


            Walk San Francisco is skeptical that the Segway HT will do more than cannibalize trips already made on foot. “Segways and motorized scooters are not significantly faster than walking unless they are operated at speeds unsafe for pedestrians.”


            Furthermore, they doubt that the current Segway would provide a useful tool to provide the “last mile” for trips made by transit: “Most walking trips in an urban setting are made in conjunction with transit. Segway devices cannot be used on most forms of transit, especially during crowded rush hour periods. Segways weigh 80 pounds, so they can’t be lifted up stairs or onto buses.”[15]


            According to RIDES’ 2001 Commute Profile, only 14% of Bay Area commuters cited barriers keeping them from bicycling to work which would be solved by operating a Segway HT on sidewalks: “Don’t Feel Safe” (10%), “No place to change/shower” (1%) or “Need to get in shape first” (3%).


            The 2001 Commute Profile also shows an average commute trip distance for San Franciscans of 13 miles, which is far beyond the reasonable range of a Segway HT; the report doesn’t indicate what percentage of trips are short enough to be convertible to a Segway HT.


            Segway’s own marketing presents contradictory messages as to whether they believe their device could substantially reduce urban automobile usage. In their first, widely-circulated promotional video, Dean Kamen explains, “I don’t think of this as an alternative to cars… This device is an improvement on walking.” 


However, in their current consumer promotional video, the narrator explains how the Segway HT will achieve for urbanites what Henry Ford accomplished in the 20th century for rural Americans (as previously quoted).


            A browse through their executive biographies shows that of traditional engineering/manufacturing business management; no experience in urban planning or pedestrian advocacy appears, let alone an advisory board of such specialists. Perhaps unsurprisingly, no pedestrian advocacy groups have reported being courted by Segway’s lobbyists to be swayed to the utility and legitimacy of the Segway HT.


            This may be the company’s downfall as a consumer product; the sole party who will certainly benefit economically by the Segway HT’s adoption as a consumer product is Segway itself. Given its clear potential risk to children, senior citizens, and other pedestrians, these groups have the potential to mobilize and hinder or bar its adoption on their local sidewalks.


            Continuing Time Magazine’s comparison to Steve Jobs’s original Macintosh introduction, Dean Kamen and Segway do not explain why consumers would choose to purchase their new invention — it’s taken for granted that everyone would want one.


            Indeed, although the Macintosh initially sold briskly due to early adopters and gadget fans, its sales plummeted for several years until a third party invented the “killer application” of desktop publishing.[16]


            It’s unclear for the Segway HT what its “killer application” will be for consumers, or if it will even have one. Even if legalized, it offers users little-to-no benefit as a tool for traveling on congested urban core sidewalks, as the Segway HT will be hindered by the 3 mph speed of the existing, dense pedestrian traffic, and not likely to be allowed during peak commute hours on existing transit systems, which already restrict bicycles.


            Its unveiling, at least, generated mass attention and tacit media acknowledgement of the automobile problem within urban America — even if it proposed to address the problem through the means of marketing yet another costly, privately owned technological MacGuffin to correct the problems created by an imbalanced adoption of the last one.


            American cities aren’t choked with automobiles by fate or by necessity, but by specific government subsidies, tax laws, and policies that have driven individuals to adopt them as the dominant transportation mode. Indeed, through Urban Renewal, we spent billions in tax dollars to “redesign our cities” — with a bulldozer and wrecking ball — for that very purpose.


If we’re going to redesign our cities a second time, we shouldn’t do it to merely substitute our dependency on private automobiles with a dependency on a newer privately owned product, controlled by a single corporate entity.


As a visit to European or Japanese cities would reveal, becoming an “empowered pedestrian” doesn’t require any newfangled self-balancing scooter technologies.


True pedestrian empowerment arises from an urban density that promotes elegant and timely public transit instead of automobile-clogged intersections, graceful and practical walking paths free of curb cuts and high-speed obstacles, and mixed-use development that provides all the necessities of life within a rewarding stroll.

[1] Time Magazine, December 2nd 2001.

[2] Time Magazine, December 2nd 2001.

[3] EE Times, December 10th 2001

[4] Segway.com web site

[5] Derived from a spreadsheet on Columbia Children’s Hospital – Center for Injury Research and Policy’s web site.

[6] Derived from Segway’s “e-series” product specification, which supports a 250 pound passenger with 75 pounds of cargo, riding on a 95 pound scooter.

[7] Segway promotional video

[8] From Dr. Gary Smith’s testimony against SB231, which would enable Segway HTs on Ohio sidewalks.

[9] From an unpublished Walk SF position paper.

[10] Also from an unpublished Walk SF position paper.

[11] Also from Dr. Gary Smith’s SB231 testimony.

[12] BBC News, May 14th 2002.

[13] From promotional video on www.segway.com

[14] CNN.com, 12/03/2001.

[15] Also from unpublished Walk SF Segway position paper.

[16] CRN, July 2nd 2002.