Cruising for parking

Article (PDF Available)inTransport Policy 13(6):479-486 · February 2006with 751 Reads
DOI: 10.1016/j.tranpol.2006.05.005 · Source: RePEc
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Abstract
Suppose curb parking is free but all the spaces are occupied, and off-street parking is expensive but immediately available. In this case, you can cruise to find a curb space being vacated by a departing motorist, or pay for off-street parking right away. This paper presents a model of how drivers choose whether to cruise or to pay, and it predicts several results: you are more likely to cruise if curb parking is cheap, off-street parking is expensive, fuel is cheap, you want to park for a long time, you are alone in the car, and you place a low value on saving time. The model also predicts that charging the market price for curb parking—at least equal to the price of adjacent off-street parking—will eliminate cruising. Because the government sets curb parking prices, planners and elected officials strongly influence drivers’ decisions to cruise. The failure to charge market rates for curb parking congests traffic, pollutes the air, wastes fuel, and causes accidents. Between 1927 and 2001, studies of cruising in congested downtowns have found that it took between 3.5 and 14 min to find a curb space, and that between 8 and 74 percent of the traffic was cruising for parking.
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Transport Policy 13 (2006) 479–486
Cruising for parking
Donald C. Shoup
Department of Urban Planning, University of California, Los Angeles, Los Angeles, CA 90095-1656, USA
Available online 24 July 2006
Abstract
Suppose curb parking is free but all the spaces are occupied, and off-street parking is expensive but immediately available. In this case,
you can cruise to find a curb space being vacated by a departing motorist, or pay for off-street parking right away. This paper presents a
model of how drivers choose whether to cruise or to pay, and it predicts several results: you are more likely to cruise if curb parking is
cheap, off-street parking is expensive, fuel is cheap, you want to park for a long time, you are alone in the car, and you place a low value
on saving time. The model also predicts that charging the market price for curb parking—at least equal to the price of adjacent off-street
parking—will eliminate cruising. Because the government sets curb parking prices, planners and elected officials strongly influence
drivers’ decisions to cruise. The failure to charge market rates for curb parking congests traffic, pollutes the air, wastes fuel, and causes
accidents. Between 1927 and 2001, studies of cruising in congested downtowns have found that it took between 3.5 and 14 min to find a
curb space, and that between 8 and 74 percent of the traffic was cruising for parking.
r2006 Elsevier Ltd. All rights reserved.
Keywords: Parking; Pricing; Congestion
1. Introduction
My father didn’t pay for parking, my mother, my
brother, nobody. It’s like going to a prostitute. Why
should I pay when, if I apply myself, maybe I can get it
for free.
George Costanza
When a resource is communally owned, the right of
‘‘first possession’’ means that anyone who captures the
resource has the right to use it. Free curb parking is an
example of communal ownership, because drivers occupy it
on a first-come, first-served basis. If all the curb spaces are
occupied, drivers must cruise to find a space vacated by a
departing car. Cruising for parking probably began soon
after the wheel was invented.
2. Cruising in the 20th century
Cruising creates a mobile queue of cars that are waiting
for curb vacancies, but no one can see how many cars are
in the queue because the cruisers are mixed in with other
cars that are actually going somewhere. Perhaps because
cruising is invisible, most transport economists and
planners have neglected it as a source of congestion.
Nevertheless, a few researchers have attempted to estimate
the volume of cruising and the time it takes to find a curb
space. They have analyzed videotapes of traffic flows,
interviewed drivers who park at the curb, and have
themselves cruised. Table 1 shows the results of every
study of cruising I have been able to find. Between 8 and 74
percent of the traffic was cruising for parking, and the
average time to find a curb space ranged between 3.5 and
14 min. The wide variance in the estimates of cruising
surely reflects reality. On most streets most of the time,
none of the traffic is cruising, but on some streets some of
the time, most of the traffic may be cruising.
Are these studies dating back to 1927 only of historical
interest? The data were probably not very accurate when
they were collected, and the results depend on the time and
place where they were collected. The data are selective
because researchers study cruising only where they expect
to find it. Conditions have also changed since many of the
observations were made. Nevertheless, cruising itself has
not changed, and the studies at least show that searching
for curb parking has wasted time and fuel for many
ARTICLE IN PRESS
www.elsevier.com/locate/tranpol
0967-070X/$ - see front matter r2006 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tranpol.2006.05.005
Tel.: +1 310 825 5705; fax: +1 310 206 5566.
E-mail address: shoup@ucla.edu.
decades. Because curb parking is underpriced and over-
crowded in the busiest parts of most of the world’s big
cities, the sun never sets on cruising.
Even a small search time per car can create a surprising
amount of traffic. Consider, for example, a congested
downtown where it takes three minutes to find a curb space
and the parking turnover is 10 cars per space per day. Each
curb space generates 30 min of cruising time per day. If the
average cruising speed is 10 miles an hour, each curb space
generates five vehicle miles traveled (VMT) per day. Over a
year, this cruising amounts to 1825 VMT, greater than
halfway across the United States, for each curb space.
Because this cruising adds to traffic that is already
congested, it makes a bad situation even worse.
Where on-street parking is cheaper than off-street
parking, cruising is individually rational. Collectively,
however, it congests traffic, causes accidents, wastes fuel,
pollutes the air, and degrades the pedestrian environment.
Cities create all these problems when they underprice curb
parking. Underpricing of anything creates a shortage, and
curb parking is no exception. Underpriced curb parking is
gross mismanagement of scarce urban land, with wide-
spread ramifications for transportation, cities, the econo-
my, and the environment.
3. Choosing to cruise
When we cruise for parking on crowded streets, we
rarely seem to think about how we end up in this mobile
purgatory. How do you choose whether to cruise or to pay?
A simple model of the benefits and costs of cruising can
help answer this question. The model predicts several
results: you are more likely to cruise if curb parking is
cheap, off-street parking is expensive, fuel is cheap, you
want to park for a long time, you are alone in the car, and
you place a low value on saving time.
To set the scene for the model, suppose curb parking is
free but so crowded that you have to spend time hunting
for a space. You can park off-street without waiting, but
you have to pay for it. Given the tradeoff between spending
time to find curb parking or spending money to pay for off-
street parking, should you cruise or pay?
Drivers do not explicitly calculate whether to cruise or to
pay, but several factors influence the decision. To help
understand the choice, consider the following variables
(and their dimensions).
1
pprice of curb parking ($/h)
mprice of off-street parking ($/h)
tparking duration (h)
ctime spent searching for parking at the curb (h)
ffuel cost of cruising ($/h)
nnumber of people in the car (persons)
vvalue of time spent cruising ($/h/person)
We can use these seven variables to compare the time
and fuel cost of cruising with the money cost of parking
off-street. I will, for the moment, assume that the walking
time from the parked car to the final destination is the same
for both curb and off-street parking.
First, consider how much you save on parking if you can
find a curb space. The price of parking at the curb is p
dollars per hour, and the price of parking off-street is m
dollars per hour, so parking at the curb rather than off-
street saves mpdollars per hour. The amount you save by
parking at the curb is the duration (t) multiplied by the
difference between the prices of off-street and curb
parking, or t(mp). For example, if curb parking is free,
off-street parking costs $1 an hour, and you park for two
hours, you save $2 by parking at the curb.
2
Second, cruising has a fuel cost. If your car consumes
fuel at a rate of fdollars per hour of cruising for parking,
and you cruise for chours, the total cost of fuel spent
ARTICLE IN PRESS
Table 1
Twentieth century cruising
Year City Share of traffic
cruising (percent)
Average search
time (min)
1927 Detroit (1) 19%
1927 Detroit (2) 34%
1933 Washington 8.0
1960 New Haven 17%
1965 London (1) 6.1
1965 London (2) 3.5
1965 London (3) 3.6
1977 Freiburg 74% 6.0
1984 Jerusalem 9.0
1985 Cambridge 30% 11.5
1993 Cape Town 12.2
1993 New York (1) 8% 7.9
1993 New York (2) 10.2
1993 New York (3) 13.9
1997 San Francisco 6.5
2001 Sydney 6.5
Average 30 8.1
Note: The numbers after Detroit, London, and New York refer to
different locations within the same city.
Sources: Simpson (1927),Hogentogler et al. (1934),Huber (1962),Inwood
(1966),Bus+Bahn (1977),Salomon (1984),O’Malley (1985),Clark
(1993a, b),Falcocchio et al. (1995),Saltzman (1994), and Hensher (2001).
1
For the model, I assume that drivers are indifferent between curb and
off-street parking if the price and the time required to find a space are the
same in both cases. There are no time limits, and drivers pay in a linear
proportion to the number of minutes parked in both cases. In reality, curb
parking is often more convenient if a space is available right in front of the
final destination because the walking distance from the car to the
destination is shorter. Curb parking is also often available in smaller
increments (such as 6 or 10 min) while off-street parking is available only
in larger increments (such as 20 or 30 min), and the price per minute
declines for longer stays.
2
I assume that you know in advance how long you want to park, and
that you pay only for the exact time that you park. The parking charge is a
linear function of the number of minutes you park, with no advance
commitment to how long you park. Shoup (2003) describes parking meters
that allow you to pay for the exact time that you park, determined ex post.
D.C. Shoup / Transport Policy 13 (2006) 479–486480
for cruising is fc.
3
For example, if the fuel cost is $1
per hour and you cruise for 6 min (0.1 h), the fuel
cost is 10b. (If drivers ignore the cost of fuel for cruising,
f¼0.)
Third, cruising has a time cost. The value you place on
saving time depends on your income and on many factors
that are unique to each trip: whether you are in a hurry, the
weather, the scenery, safety, your health, and so on. The
value of time will, of course, vary from person to person,
but even the same person will place a higher or lower value
on time depending on the circumstances. Each person’s
time cost of cruising is the value of time (v) multiplied by
the time spent cruising (c), or vc. Because every person in
the car must spend the same time cruising, the total time
cost for everyone in the car is the number of people in the
car (n) multiplied by each person’s time cost (vc), or nvc.
4
So if you are alone in the car, value time savings at $9 an
hour, and cruise for 6 min before parking, your cost of time
spent cruising is 90b. Adding one passenger in the car
doubles the time cost to $1.80. A second passenger makes it
$2.70, and so on.
The money saved by parking at the curb and the cost of
cruising for a curb space are,
tðmpÞ, (1) money saved by parking at
the curb
fc, (2) money cost of cruising for
curb parking
nvc, (3) monetized cost of time spent
cruising for curb parking
fc þnvc ¼cðfþnvÞ, (4) money and (monetized) time
cost of cruising for curb
parking
At what point does cruising for curb parking become
more expensive than paying to park off street right away?
Let c* denote the time that equates the time-and-fuel cost
of cruising with money cost of off-street parking. There is
no cost difference between cruising and paying if you
expect to spend exactly c* minutes to find a curb space, so
you are indifferent between the two choices.
5
This
equilibrium occurs when the money saved from parking
at the curb, t(mp), equals the money and time cost of
cruising, c*(f+nv). So if you expect that it will take longer
than c* to find a curb space, you should pay to park off-
street. But if you expect that it will take less than c*, then
you should cruise.
The break-even point occurs where the cost of cruising
equals the savings from parking at the curb.
cðfþnvÞ¼tðmpÞ(5)
The search time at which you are indifferent between
cruising and paying is,
c¼tðmpÞ
fþnv (6)
At time c*, you realize no net savings by parking at the
curb instead of off-street. The money the city loses from
underpriced curb parking does not accrue to you or to
anyone else, but is instead dissipated in time and fuel spent
cruising. And because each driver in congested traffic
imposes time delays on all other drivers, cruising makes
all drivers worse off, including those who are not trying
to park.
4. Equilibrium search time: an example
We can use an example to illustrate the equilibrium
search time. Suppose you want to park for one hour
(t¼1), off-street parking costs $1 an hour (m¼1), and
curb parking is free (p¼0). You thus save $1 by parking at
the curb rather than off-street. If you drive 10 miles an
hour and your car gets 20 miles per gallon of gasoline, the
cruising consumes half a gallon of gasoline an hour. If
gasoline costs $2 a gallon, the fuel cost is $1 an hour
(f¼1). You are alone in the car (n¼1) and your time is
worth $9 per hour saved (v¼9). The equilibrium search
time, c*, is
c¼tðmpÞ
fþnv ¼1ð10Þ
1þ19¼0:1h ¼6 min
In this case it is worth spending up to 6 min to find a curb
space. If fuel costs $1 an hour, and you cruise for 6 min
(0.1 h), you spend 10bfor fuel ($1 0.1). You save $1 on
parking for an hour, so your net saving from parking at the
curb is 90b($1 saving on parking minus 10bspent for
fuel). In a sense, you ‘‘earn’’ $9 an hour for the time spent
cruising (90bsaved for 0.1 h of cruising). If you value time
savings at $9 an hour, 6 min is the search time that leaves
you indifferent between searching for curb parking and
paying to park off-street immediately. You are no better
off parking free at the curb after searching for 6 min than if
you had paid $1 to park off-street immediately.
6
ARTICLE IN PRESS
3
The fuel cost per hour of cruising is the cost of fuel per gallon divided
by the miles cruised per gallon and then multiplied by the cruising speed.
For example, if gasoline costs $1 per gallon, and your car gets 20 miles per
gallon, cruising costs 5bper mile. If you cruise at 20 miles per hour, the
fuel cost of cruising is $1 per hour.
4
The cost of time spent cruising, v, may differ among persons in the car.
If everyone’s value of time is weighted equally, we can interpret vas the
average value of time.
5
The time spent walking from the car to the final destination is neglected
here.
6
If it takes less than 6 min to find a curb space, you earn more than $9
an hour by cruising, so cruising for free curb parking is cheaper than
paying to park off-street immediately. If it takes more than 6 min to find a
curb space, you earn less than $9 an hour by cruising, so paying to park
off-street immediately is cheaper than cruising for free curb parking. This
appears to suggest that cruising should allocate curb parking to drivers
who place a lower value on saving time spent driving. Nevertheless, a
driver who has a higher value of time and wants to park for a longer
duration may be willing to cruise longer than a driver who has a lower
value of time who wants to park for a shorter duration because
c¼tðmpÞ=ðfþnvÞ, with parking duration in the numerator and value
of time in the denominator.
D.C. Shoup / Transport Policy 13 (2006) 479–486 481
This example suggests two results. First, ‘‘free’’ curb
parking is not really free. Although cruising’s costs are not
directly out-of-pocket (like money put in a parking meter),
they are incurred in the form of time and fuel used to find a
curb space. ‘‘Free’’ curb parking leaves the driver no better
off, but everyone else is worse off because cruising congests
traffic and pollutes the air; the city also loses the money it
would have received if it had charged the market price for
curb parking. Second, since the time spent cruising is the
price of curb parking, this price depends on each person’s
opportunity cost of time.
7
In this example, solo drivers who
value time savings at more than $9 an hour should pay to
park right away, and those with a lower value of time
should cruise. Free curb parking thus attracts solo drivers
who place a low value on saving time. Areas where curb
parking is free, many cars are solo driven, and drivers
place a low value on saving time will therefore have long
search times.
This equilibrium-search-time example also suggests that
raising the price of curb parking reduces the parkers’ time-
and-fuel cost of cruising by as much as it increases their
money payments for parking. The net burden on parkers is
zero, and the price rise converts private waste into public
revenue.
5. The wages of cruising
Cities create the incentive to cruise when they charge less
for curb parking than the price of adjacent off-street
parking. To examine this incentive, I collected data on the
price of curb and off-street parking for an hour at noon at
the same location—City Hall—in 20 cities throughout the
US.
8
Table 2 shows the results. The average price is $1.17
an hour for curb parking, and $5.88 an hour off-street.
Cruising saves drivers the most money in New York, where
the price of off-street parking is $14.38 for the first hour,
but curb parking is only $1.50. Cruising saves money in all
cities except Palo Alto and San Francisco. In the 20 cities,
the average price of curb parking is only 20 percent of the
price of off-street parking, and the highest price of curb
parking is only $2 an hour.
The supply of parking affects its price. Boston’s
high price of off-street parking ($11) stems in part
from a cap the city has placed on the number of off-
street parking spaces available downtown. The parking
inventory is frozen at its 1975 level—35,500 spaces.
Developers who want to build new parking spaces
must buy licenses owned by existing parking facilities that
close.
9
This supply cap drives up the market price of off-
street parking and produces an ironic outcome: combined
with the low price of curb parking, the higher price of off-
street parking increases the incentive to cruise. Boston
limits the private off-street parking supply, but fails to
price its own public curb parking properly. A survey in
2003 found that the average price for off-street parking
in the Boston CBD was $390 a month, and $30 a day.
10
In
contrast, Boston charges the same price ($1 an hour) for all
ARTICLE IN PRESS
Table 2
The wages of cruising for parking at city hall (curb parking one hour at
noon)
City State Price of parking for
one hour
Savings for
finding a curb
space
Curb Off-street
(1) (2) (3) $/h (4) $/h (5) ¼(4)–(3) $
Baltimore MD $2.00 $6.00 $4.00
Berkeley CA $0.75 $1.00 $0.25
Boston MA $1.00 $11.00 $10.00
Buffalo NY $1.00 $3.00 $2.00
Cambridge MA $0.50 $4.00 $3.50
Chicago IL $1.00 $13.25 $12.25
Houston TX $0.25 $1.50 $1.25
Long Beach CA $2.00 $2.50 $0.50
Los Angeles CA $1.50 $3.30 $1.80
New Orleans LA $1.25 $3.00 $1.75
New York City NY $1.50 $14.38 $12.88
Palo Alto CA $0.00 $0.00 $0.00
Pasadena CA $1.00 $6.00 $5.00
Philadelphia PA $1.00 $3.00 $2.00
Portland OR $1.00 $1.50 $0.50
San Diego CA $1.00 $6.00 $5.00
San Francisco CA $2.00 $2.00 $0.00
Santa Barbara CA $0.00 $5.00 $5.00
Santa Monica CA $0.50 $4.20 $3.70
Seattle WA $1.00 $8.00 $7.00
Average $1.17 $5.88 $4.71
Assumptions: A solo driver parks for one hour at noon on a weekday.
7
Smolensky, Tideman, and Nichols (1972, 95) say, ‘‘Queues can be
viewed as prices assessed in time, and time prices, like money prices, ration
according to the tastes, income and opportunity costs of buyers.’’
8
The cities are an opportunistic sample of places where my research
assistants and I visited and were able to gather the data. Nevertheless, the
sample shows that curb parking is probably much cheaper than off-street
parking in many big and small cities. City Hall was chosen because it is a
standard reference point that everyone can recognize. The data were
collected in 2001–2003.
9
Boston Transportation Department (2001). The Boston Air Pollution
Control Commission administers the ‘‘parking freeze’’ in Boston Proper
(the downtown). The number of spaces available to the general public is
frozen at the 1975 level, but the Boston Air Pollution Control Commission
may grant exemptions to private off-street parking that is available
exclusively to employees, guests, or customers in a building. Residential
parking isn’t capped. The total off-street parking supply increased by only
9 percent between 1977 and 1997, and in 1997 the 35,500 public parking
spaces represented 60 percent of the total 59,100 off-street spaces in
Boston Proper. Additional freezes apply in East Boston, South Boston,
and at Logan Airport. Portland, Oregon, had a similar limit on the
number of parking spaces—known as the parking lid—in the CBD. It was
replaced in 1995 by limit on 0.7 spaces per 1000 square feet of net leasable
area, in part because historic buildings without any parking were losing
nearby surface parking lots and were increasingly difficult to lease
(Portland TriMet, 2002, 3–9).
10
Colliers International (2003, pp. 28–29). The highest price for
unreserved parking in Boston’s CBD was $600 a month, and the lowest
was $285 a month.
D.C. Shoup / Transport Policy 13 (2006) 479–486482
meters in the city. Far from using prices to manage the
demand for curb parking, Boston underprices curb parking
and thus encourages drivers to cruise for it.
Boston’s off-street parking cap makes sense as a way to
reduce congestion on routes to the city, but its failure to
follow through with market prices for curb parking
increases congestion in the city. Everyone would criticize
off-street parking operators if long lines of cars regularly
spilled into the streets and congested traffic because the lots
and garages were always full. Nevertheless, cities create the
same result with curb parking by underpricing it, and
nobody notices because the cars hunting for curb parking
are hidden in the general traffic flow.
6. Two pricing strategies
Cities can use two pricing strategies to discourage
cruising. The first is to charge the market price for curb
parking. When the prices of curb and off-street parking are
equal (p¼m), the equilibrium cruising time (c*) is zero.
c¼tðmpÞ
fþnv ¼tð0Þ
fþnv ¼0
If curb parking costs the same as off-street parking, why
drive around hunting for a curb space? Since curb parking
(after you spend time and money to find it) costs the same
as off-street parking, you don’t save any money by
cruising. If all curb spaces are occupied and there is no
economic incentive to cruise, you should park off-street
without wasting time and fuel.
11
If curb parking remains free, however, a second strategy
to discourage cruising is to reduce the price of off-street
parking to zero. The logic is the same: if off-street parking
is free, why drive around looking for a curb space? Since
the prices of curb and off-street parking are again equal
(m¼p¼0), the equilibrium time is again zero.
c¼tðmpÞ
fþnv ¼tð0Þ
fþnv ¼0
Cities can therefore eliminate cruising either by charging
market prices for curb parking or by requiring enough off-
street spaces to reduce the price of off-street parking to
zero. The price of curb parking is one of the few policy
variables that cities control directly, but almost all
American cities have chosen the wrong policy: require
plentiful off-street parking rather than charge fair market
prices for scarce curb parking.
7. Elasticities
Table 3 shows how each of the variables in the model
affect the decision whether to cruise or to pay. The second
column shows the partial derivatives of c* (the maximum
time a driver is willing to cruise) with respect to the
variables in the first column. Six factors affect the decision
to cruise: (1) the price of curb parking, (2) the price of off-
street parking, (3) parking duration, (4) the price of fuel,
(5) the number of persons in the car, and (6) the value
of time.
The third column shows the elasticity of c* with respect
to each variable. The coefficient of elasticity is denoted by Z
(the Greek letter eta). These elasticities show how a small
change in each variable increases or decreases the time a
driver is willing to cruise. Five results stand out.
First, Z
p
(the elasticity of search time with respect to the
price of curb parking) depends only on the prices of curb
and off-street parking. The elasticity is low when curb
parking is relatively cheap, which means that raising the
price—say, doubling it from 10bto 20ban hour—will
have little effect on curb vacancies. This result may lead
some to conclude that the demand for curb parking is
inelastic, and that raising the price of curb parking will not
produce vacancies. But as the price of curb parking
approaches the price of off-street parking, a small increase
can create curb vacancies and reduce congestion. The
demand for curb parking may be completely inelastic until
its price exceeds that of off-street parking, at which point it
can suddenly become very elastic.
12
Because the variables
ARTICLE IN PRESS
Table 3
Equilibrium search time
Variable Partial derivative of c* Elasticity of c*
p(curb parking price) qc
qp¼ t
fþnv o0Zp¼ p
mpo0
m(off-street parking
price)
qc
qm¼þ t
fþnv 40Zm¼þ m
mp40
t(parking duration) qc
qt¼þmp
fþnv 40Zt¼þ1
f(fuel cost of cruising) qc
qf¼tðmpÞ
ðfþnvÞ2o0Zf¼ f
fþnv o0
n(number of persons) qc
qn¼tvðmpÞ
ðfþnvÞ2o0Zn¼ nv
fþnv o0
v(value of time) qc
qv¼ntðmpÞ
ðfþnvÞ2o0Zv¼ nv
fþnv o0
Notes: The length of time (c*) a motorist is willing to search for curb
parking is: c¼tðmpÞ
fþnv . The elasticity (Z
i
)ofc* with respect to variable iis:
Zi¼qc=qi
c=i.
11
If drivers prefer curb to off-street parking, the price of curb parking
must rise above the price of off-street parking to create curb vacancies and
discourage cruising.
12
For example, when the price of curb parking is 25ban hour and the
price of off-street parking is $1 an hour, Zp¼ð:25Þ=ð1:25Þ¼0:33;
therefore, raising the price by 10 percent reduces the time drivers are
willing to cruise by only 3.3 percent. But when the price of curb parking is
75ban hour, Zp¼ð:75Þ=ð12:75Þ¼3; therefore, raising the price by 10
percent reduces the time drivers are willing to cruise by 30 percent. Even
this large reduction in search time may not produce many curb vacancies,
however. If curb parking is cheaper than off-street parking, the main effect
D.C. Shoup / Transport Policy 13 (2006) 479–486 483
  • Article
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    To solve the difficult parking problem, developing a mechanical parking device is a practical approach. Aiming at longitudinal parking, a novel compact double-stack parking system is put forward based on a 1-DOF (degree of freedom) cam-linkage double-parallelogram mechanism. Due to the unique structure, the whole device can be driven by a single motor to realize three motion periods, including lifting, translation, and fillet transition. Meanwhile, all parts of this compact mechanism can be well contained in the filleted rectangular trajectory. This rectangular trajectory is essential that we no longer need to take out the ground vehicles so as to realize stack parking. Furthermore, to overcome the singularity collinear problem of the parallelogram which may lead to the polymorphic state, the double-parallelogram mechanism is proposed to maintain the orientation of the parking platform. The digital simulation and kinetostatic analysis results demonstrate the feasibility that this novel cam-linkage double-parallelogram mechanism can improve the space utilization of the residential area, alleviate the parking problem, and can be quickly put into application on campuses or streets in a short period. (More details can be found at https://youtu.be/lmwdDsUXUw8)
  • Article
    Excessive search for parking spots in congested areas contributes to additional travel delays and negative socio-economic impacts. While managing parking utilization to address the agency's objectives, it is often very beneficial to reflect the diversity of users' behaviors and their travel choices. This paper develops a stochastic dynamic parking management model, under competitive user-agency perceptions and uncertain user demand and parking occupancy, to simultaneously minimize the total travelers' costs and maximize the parking agency's revenue. The problem is formulated into a dynamic programming model and solved using a stochastic look-ahead technique based on the Monte Carlo tree search algorithm to determine optimal actions on parking price assignment and spot utilization over time. The numerical experiments on a hypothetical and empirical case study are conducted to show the performance of the proposed algorithm and to draw managerial insights. The results are compared with those of benchmark algorithms, which indicate that the proposed methodology can determine near-optimal solutions efficiently.
  • Conference Paper
    Growing cities always have parking challenges and they are in need for creative ideas to solve this issue and avoid the time wasted in searching for empty parking spots. To overcome the problem, this paper proposes a simple solution using a low-cost cloud-based system design. The design will be initially implemented on campus in one parking lot at the University of Central Oklahoma. The goal is to make the faculties and students life easier by guiding them to empty parking spots. The design of the proposed system is discussed in this paper and preliminary data are presented including the cost function. The system will guide the users through the web-based application.
  • Article
    En este trabajo se discuten los desafíos para la política pública de la irrupción de las pla­taformas de transporte en el mundo durante la última década. Entre los temas abordados están los efectos de esta innovación tecnológica sobre la seguridad vial, los desafíos tributarios y de financiamiento de los sistemas de transporte público, los estándares laborales, la calidad de ser­vicio, privacidad de la información, así como las consecuencias sociales y distributivas del auge de estas plataformas. El artículo revisa la literatura académica existente respecto a estos temas, destacando la evidencia empírica disponible y pone un énfasis particular sobre los posibles im­pactos de las plataformas sobre la congestión urbana, asunto que recientemente está recibiendo más atención de los investigadores. En las conclusiones se presenta una propuesta regulatoria que permite aprovechar los beneficios que ofrecen las plataformas de transporte, pero evitando o minimizando sus impactos negativos.
  • Article
    This article is the first in the literature to investigate the network traffic equilibrium for traveling and parking with autonomous vehicles (AVs) under a fully automated traffic environment. Given that AVs can drop off the travelers at their destinations and then drive to the parking spaces by themselves, we introduce the joint equilibrium of AV route choice and parking location choice, and develop a variational inequality (VI)‐based formulation for the proposed equilibrium. We prove the equivalence between the proposed VI model and the defined equilibrium conditions. We also show that the link flow solution at equilibrium is unique, even though both the route choices and parking choices are endogenous when human‐occupied AV trips (from origin to destination) and empty AV trips (from destination to parking) are interacting with each other on the same network. We then develop a solution methodology based on the parking‐route choice structure, where we adjust parking choices in the upper level and route choices in the lower level. Numerical analysis is conducted to explore insights from the introduced modeling framework for AV network equilibrium. The results reveal the significant difference in network equilibrium flows between the AV and non‐AV situations. The results also indicate the sensitivity of the AV traffic pattern to different factors, such as value of time, parking pricing, and supply. The proposed approach provides a critical modeling device for studying the traffic equilibrium under AV behavior patterns, which can be used for the assessment of parking policies and infrastructure development in the future era of AVs.
  • Chapter
    Growing cities always have parking challenges and they are in need for creative ideas to solve this issue and avoid the time wasted in searching for empty parking spots. To overcome the problem, this paper proposes a simple solution using a low-cost cloud-based system design. The design will be initially implemented on campus in one parking lot at the University of Central Oklahoma. The goal is to make the faculties and students life easier by guiding them to empty parking spots. The design of the proposed system is discussed in this paper and preliminary data are presented including the cost function. The system will guide the users through the web-based application.
  • Article
    Does unmarked on-street parking accommodate more cars—because smaller cars take less space? Or is unmarked spacing actually less efficient, because of the mismatch effect of very small cars? Should we charge shorter cars less for parking based on their space saving contribution? With many factors in effect, the judgement is not easy. For the first time this study uses computer simulation to assign queues of randomly generated vehicles to marked and unmarked spaces using a parallel world method, to directly test which method is more efficient and can accommodate more cars. Simulation results show that unmarked spacing is more efficient only when the curb is shorter, or not close to any integer times of the optimal length of one marked space, and when drivers are all considerate when choosing the parking location. Under other situations, marked spacing accommodates more cars. This simulation study also found that vehicle downsizing only significantly improves parking efficiency if the vehicle is downsized to two-seaters that can vertically park. In other cases, vehicle downsizing only helps the owners of the downsized vehicles themselves, and making it more difficult for all other people to find parking. To better benefit from vehicle downsizing, a new type of “block-based” spacing is proposed, which achieves some of the flexibility of unmarked spacing and keeping the mismatch-effect relatively low.
  • Article
    Full-text available
    The deployment of intelligent connected vehicles (ICVs) is regarded as a significant solution to improve road safety, transportation management, and energy efficiency. This study assessed the safety, traffic, environmental, and industrial economic benefits of ICV deployment in China under different scenarios. A bottom-up model was established to deal with these impacts within a unified framework, based on the existing theories and literature of ICVs’ cost–benefit analysis, as well as China’s most recent policies and statistics. The results indicate that the total benefits may reach 13.25 to 24.02 trillion renminbi (RMB) in 2050, while a cumulative benefit–cost ratio of 1.15 to 3.06 suggests high cost-effectiveness. However, if the government and industry only focus on their own interests, the break-even point may be delayed by several years. Hence, an effective business model is necessary to enhance public–private cooperation in ICV implementation. Meanwhile, the savings of travel time costs and fleet labor costs play an important part in all socioeconomic impacts. Therefore, the future design of ICVs should pay more attention to the utilization of in-vehicle time and the real substitution for human drivers.
  • Conference Paper
    The smart parking system is a major component of the smart city concept, especially in the age of the Internet of Things (IoT). It attempts to take the stress out of finding a free parking space in crowded places, mostly during peak times. This paper focuses on implementing a secure smart parking solution based on the publish-subscribe communication model for exchanging a huge volume of data with a large number of clients while minimizing the power consumption. The Elliptic Curve Cryptography (ECC) was adopted in this paper as a promising substitution to traditional public key cryptography such as Rivest-Shamir-Adleman (RSA). The implemented system provides several functional services including parking vacancy detection, real-time information for drivers about parking availability, driver guidance, and parking reservation. Moreover, it provides security mechanisms for both network and application layers. Performance and power consumption experiments using a testbed show the efficiency and practicality of the implemented system, essentially with the IoT resource-constrained devices. Our findings demonstrate achieving energy consumption reductions of up to 54% and a CPU usage decrease of up to 55% compared to the existing solutions.
  • An inquiry on the traffic congestion impacts of parking and pricing policies in the Manhattan CBD,'' prepared for the New York City Department of Transporta-tion Division of Parking and the University Transportation Research Center, Region II
    • J Falcocchio
    • D Jose
    • P Elena
    Falcocchio, J., Jose, D., Elena, P., 1995. An inquiry on the traffic congestion impacts of parking and pricing policies in the Manhattan CBD,'' prepared for the New York City Department of Transporta-tion Division of Parking and the University Transportation Research Center, Region II. Polytechnic University of New York Transporta-tion Training and Research Center, New York, February 1995.
  • Modal diversion Handbook of Transport Systems and Traffic Control
    • D Hensher
    Hensher, D., 2001. Modal diversion. In: Kenneth, B., David, H. (Eds.), Handbook of Transport Systems and Traffic Control. Pergamon, Amsterdam, pp. 107–123.
  • Policies to Manage Parking in the Central City Area. City Planning Department, TP 608/PC
    • P Clark
    Clark, P., 1993b. Policies to Manage Parking in the Central City Area. City Planning Department, TP 608/PC, Cape Town, South Africa.
  • Intangible economics of highway transportation
    • C A Hogentogler
    • E A Willis
    • J A Kelley
    Hogentogler, C.A., Willis, E.A., Kelley, J.A., 1934. Intangible economics of highway transportation. In: Proceedings of the Thirteenth Annual Meeting of the Highway Research Board, Washington, DC, December 7-8, 1933, pp. 189-205.
  • Article
    An understanding of the demand for city centre parking is an important input to policy making. This study emphasizes the importance and benefits of analysing the demand for parking at the level of individual users rather than basing analyses on traffic and parking counts. A survey of drivers' parking behaviour in Jerusalem's business centre was used. A structure is presented for analysing the driver's parking decision process and policy implications that can be drawn from disaggregate data are suggested.
  • Book
    Full-text available
    Urban planners typically set minimum parking requirements to meet the peak demand for parking at each land use, without considering either the price motorists pay for parking or the cost of providing the required parking spaces. By reducing the market price of parking, minimum parking requirements provide subsidies that inflate parking demand, and this inflated demand is then used to set minimum parking requirements. When considered as an impact fee, minimum parking requirements can increase development costs by more than 10 times the impact fees for all other public purposes combined. Eliminating minimum parking requirements would reduce the cost of urban development, improve urban design, reduce automobile dependency, and restrain urban sprawl.
  • Article
    Full-text available
    Urban planners typically set minimum parking requirements to meet the peak demand for parking at each land use, without considering either the price motorists pay for parking or the cost of providing the required parking spaces. By reducing the market price of parking, minimum parking requirements provide subsidies that inflate parking demand, and this inflated demand is then used to set minimum parking requirements. When considered as an impact fee, minimum parking requirements can increase development costs by more than 10 times the impact fees for all other public purposes combined. Eliminating minimum parking requirements would reduce the cost of urban development, improve urban design, reduce automobile dependency, and restrain urban sprawl.
  • Article
    Full-text available
    In most urban centers today, on-street metered parking systems allocate scarce short-term parking space in an unreliable and inequitable way. These systems are unreliable in the sense that a driver has a limited chance of finding a short-term parking space reasonably close to his or her destination. They are inequitable in that they fail to accurately serve equally well all segments of the parking public and the businesses these segments patronize. This paper describes three low-cost proposals designed to improve the availability of short-term on-street parking and tests them on a small scale with a simulation model.