Sunday, June 20, 2010

More on transport values

The recent posts on the transit hierarchy of needs, and numerous other posts on the same subject around the blogosphere, have led some to (informally) catalog the needs that transport users have.  By "transport", of course, I refer to all modes of personal transportation--transit, driving, bicycling, walking, or combinations thereof.

In a followup post on his blog, Cap'n Transit reduced the various factors enumerated in the University of Florida study which prompted the whole discussion, into four broad categories:  availability, value, amenities, and glamour.   In this post, I do the opposite--drilling down into quite a few more specifics, even beyond the original paper--resulting in a list of over twenty separate values.  I sort the specific values into the Cap's four toplevel categories, as they are extremely useful.  My interpretation of the four toplevel categories may disagree with the Cap'n in a few areas.

It should be noted that I am not, in this post, discussing or proposing any hierarchy or ranking of these values--different stakeholders invariably will consider different factors to be more important.  I'll reconsider this question in a followup post; for now, though, a simple catalog of transport values will be used.


Availability deals with the question of whether or not a given mode or service can reasonably be used at all for a given trip.  As mentioned in the initial post, one cannot use TriMet to reach Mount Hood; the bus doesn't go there.  (One can use transit in Portland to reach ski shuttles, on the other hand, so TriMet may well be part of a trip to the mountain). 

Values subordinate to availability include:
  • Geographic coverage is the areas that the service reaches (in a fairly broad sense).  If the nearest bus stop is down the street, the service is available; if it's 50 miles away, it's not.  The maximum acceptable distance for a service to be available varies based on quite a bit of factors--how long/far someone is willing to walk, whether or not biking or driving is an option, etc.
  • Temporal coverage has to do with what hours of the day, and days of the week, the system or route is normally operational.  Does it run 24/7?  Daylight hours only?  Rush hour only?  Weekends and holidays?   Many routes, services, and systems operate only during rush hour on weekdays; a key advantage of automobiles is that for most motorists, their car is available 24/7.  A specific concern for many planned trips is whether or not the system will be available for the return journey. 
  • Capacity, here refers to the likelihood that the service will be unavailable due to being full.  If the bus stops outside my house, but is consistently crushloaded, that negatively impacts availability.  Likewise, if a motorist needs to haul an entire soccer team to a match, a Honda Civic will lack the capacity to do the job.  A related issue is the ability to bring baggage or freight with you--can you bring a purse or briefcase?  A week's worth of groceries?  A yard of barkdust?

  • Special accommodations/restrictions refers to how usable the system or mode is for those with special needs--the disabled, the elderly, those with small children, etc.  Likewise, if someone is excluded from a system or mode, for legitimate reasons or otherwise, the system is not available to them.  (A person with a suspended drivers' license, for instance, does not have driving legally available to them).  


    Value has to do with the overall quality and costs of the service, fcusing on  factors that might make a mode objectively unsuitable for a given purpose.  Value includes factors that any reasonable user might take into account, and aren't dependent on personal taste or preference.  Imporant value-based factors include cost, timeliness, and safety.

    Cost considers how much needs to be paid to utilize the mode:  
      • Marginal costs are additional costs incurred for an additional trip--things like fares, parking fees at destinations, tolls, fuel, and amortized maintenance.
      • Access costs refer to fixed costs that must be paid to have access to the mode, but generally don't rise with additional usage.  Examples include the purchase price of a car or bike, license and insurance fees, parking charges at your primary residence.  (Note that many transit agencies permit conversion of marginal costs to access costs via the sale of monthly or yearly passes).
      • Externalized costs are those costs which are borne by society at large, rather than by users specifically.  These costs can include things which are captured and levied as taxes, as well as uncaptured externalities such as pollution, roadway damage, congestion, disruption of communities caused by the presence of infrastructure, etc.
        Timeliness refers to the ability of a mode to permit completion of a trip in a reasonable amount of time.
          • Reliability refers to how often a mode meets its service commitments (availability, schedule, headway, etc)--can the service be depended on?  This includes delays and disruptions caused by any factor, regardless of who (if anybody) is at fault.
          • Trip time refers to how quickly one can get from origin to destination--the entire journey is considered, not just in-vehicle time.
          • Frequency refers to how often the service passes by an origin or destination--an important consideration for spur-of-the-moment trips or for when a scheduled departure is missed.
            Safety refers to the risk of casualties such as loss/damage to property,injury, or death--to users of the system, operators, and the general public.
              • Risk of accidents refers to the risk of casualty due to an accident (regardless of fault).  Are operators or drivers well-trained?  Systems, vehicles, and infrastructure kept in good repair? Is the right-of-way shared with other operators who might be reckless?
              • Risk of crime refers to the risk of casualty due to a criminal act on ones journey, such as being mugged at a bus stop, or being run off the road by an enraged motorist.  Is there an adequate law enforcement/security presence?  Are the rules enforced?  
                One final note on cost: Sharp-eyed readers may notice that the above discussion treats the purchase price of an automobile as a fixed "access" cost--you can't drive to work unless you have a car, and cars cost money.  This is contrary to the treatment of car-buying found in many publications (and endorsed by the tax authorities in the United States).  Many analyses instead treat the purchase of an automobile as a capital expense, and amortize depreciation based  on the usage of the vehicle.  The IRS, in particular, will permit qualifying motorists to deduct US $0.50 per mile from their taxes--an amount which includes a significant depreciation allowance.  I treat the purchase of a car as a fixed cost for the following reasons:
                • Many motorists are able to avoid the cost of depreciation by purchasing used cars, or driving cars beyond their asset life.
                • Nonwithstanding the above, cars experience significant depreciation in value simply by being parked in the garage; a car's age is every bit as important as its mileage or condition in determining its value.   (Many other durable goods don't have this property).
                • Many motorists don't view depreciation as an expense that is borne as they drive.  A more common viewpoint is to view the purchase of an automobile as a large up-front expense (even if the purchase is financed), and which isn't amortized over mileage.  Motorists who are entitled to deduct miles driven on their personal autos from their income taxes frequently view the deduction as a windfall; as the US$0.50/mile figure well exceeds the perceived marginal costs of driving, which for many, is limited to things such as fuel, parking, and tolls.  
                I'm not arguing that this treatment of automobile expenses is correct; simply that it accurately reflects the behavior of many motorists.  A common justification for rejecting transit use among many drivers is noting that the fare for their local transit system often exceeds the value determined by multiplying fuel prices times commute distance and dividng by gas mileage--an accounting which may be flawed in numerous respects, but is commonplace nonetheless.


                Amenities refer to tangible things which make the system or mode more or less present, but aren't likely to make it outright unsuitable for a given journey.
                Unlike the "value" factors, which are more universal in nature, reasonable users are more likely to disagree on the importance of these factors.  Convenience, comfort, and other enhancements, are all examples of amenities.  Note that here,
                convenience refers to the overall ease of using a system, or conversely, the hassles encountered.  (Jarrett Walker cautions against this word in its more generic--and ambiguous--usage; however it is given a more specific meaning in this post).
                  • Ease of use refers to any special skills or abilities needed to use the system (but which can be acquired by most persons).  Must one acquire a drivers' license or insurance?  Be physically fit?   
                  • System understandability refers to the ease of navigating the system--route planning, way-finding en route, the ability of users to have up-to-date information on service disruptions, arrival times, etc.
                  • Ease of payment refers to hassles involved with collection of fares, tolls, or other charges, and the enforcement thereof.  Are passes available?  Smartcards or stored-value cards?  Must one carry exact change?   Must one equip one's vehicle with a transponder to pass by tollbooths?  Must one carry proof of payment or other documentation?
                  • Integration with community refers to the hassles involved with getting to or out of the system.  Is there adequate parking at a destination for motorists?  Does getting to/from a platform require a long or dangerous walk?  
                  • En-route hassles refer to other issues encountered, such as the need to actually operate the vehicle rather than being a passenger;  the need to transfer, etc.
                    • Comfort refers to whether or not the system is physically pleasant or unpleasant to use.  Comfort excludes safety issues, but includes numerous questions such as sitting-vs-standing, ride quality, seat quality, creature comforts such as climate control, station/platform issues (indoor vs outdoor), privacy, the need for physical exertion, etc. 
                    • Other enhancements refer to other tangible things which might add value to users of a particular mode--WiFi access, food and beverage service, onboard media (radio, television),  

                    Glamour includes non-tangible issues which may affect mode choice such as personal fulfillment, social status, etc.  Some people disregard glamour issues entirely, others choose to take retired tennis pro Andre Agassi's advice to heart.
                    • Aesthetic/novelty issues include things such as scenery en route, the architecture of system infrastructure (bridges, stations), artwork at stations, zoom and whoosh, the perceived high-tech or vintage nature of a system, the joy of driving that some experience, etc.  Novelty issues, in particular, are mainly important for tourists and persons trying a system or mode for the first time--nothing which is experienced every day will remain novel for very long.
                    • Status issues include attitudes towards other users of the system or mode, such as the avoidance of those considered unattractive, unpleasant, or undesirable (excluding legitimate safety issues); social status or acceptiblity of the mode (is it considered an elite mode of travel, or a mode of last resort), etc. 
                    • Self-actualization issues include other reasons which might affect mode choice.  These include the desire to: benefit or protect the environment, support the transit system or its workforce, show solidarity with a community, get exercise, or perform other good works.

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