potholes in edmonton
TRANSCRIPT
-
7/28/2019 Potholes in Edmonton
1/19
POTHOLES IN EDMONTONUpdated: April 4, 2013
Mack Malehttp://www.mastermaq.ca
AbstractEvery year the City of Edmonton spends a few million dollars to fill a few hundred thousand
potholes. Are potholes just a fact of life, or can we do something about them? Its time for a
more sophisticated and creative discussion about potholes in Edmonton.
-
7/28/2019 Potholes in Edmonton
2/19
1
POTHOLES IN EDMONTON
Table of ContentsPothole Primer .............................................................................................................................................. 2
How do potholes form? ............................................................................................................................ 2
How many potholes are there in Edmonton? ............................................................................................... 3
How much does Edmonton spend fixing potholes? ..................................................................................... 4
How does Edmonton compare to other Canadian cities? ............................................................................ 6
How many kilometers of road does Edmonton need to maintain? ............................................................. 8
What are the traffic trends in Edmonton that affect potholes? ................................................................... 9
How does the weather in Edmonton affect potholes? ............................................................................... 11
How often do we talk about potholes in Edmonton?................................................................................. 15
What other factors could be considered? .................................................................................................. 17
Sources ........................................................................................................................................................ 18
License......................................................................................................................................................... 18
-
7/28/2019 Potholes in Edmonton
3/19
2
POTHOLES IN EDMONTON
Pothole Primer
Heres the definition from Wikipedia:
A pothole (sometimes called a kettle and known in parts of the Western United States as a
chuckhole) is a type of disruption in the surface of a roadway where a portion of the road
material has broken away, leaving a hole.
An alternative definition, suggested in Pothole primer: A public administrators guide to understanding
and managing the pothole problem is:
Any pavement defect involving the surface, or the surface and base, to the extent that it will
cause significant noticeable impact on vehicle tires and vehicle handling.
How do potholes form?
Potholes develop when water and traffic are present at the same time. This infographic from the
Missourian illustrates this process:
-
7/28/2019 Potholes in Edmonton
4/19
3
POTHOLES IN EDMONTON
How many potholes are there in Edmonton?
The City of Edmonton generally cites an average of 400,000 potholes filled each year, and in 2012
estimated that roughly 97% of potholes would be filled. The true number of potholes is difficult to
estimate.
This chart shows the number of potholes filled in Edmonton since 2000:
That totals more than 5.6 million potholes! Using an average of 400,000 potholes per year for the period
1990-1999, we can estimate that the City of Edmonton has filled nearly 10 million potholes over the last
20 years.
386,845354,376
319,873
354,150
404,000
527,450
346,250
593,050
443,300471,000
434,950
549,600
453,600
-
100,000
200,000
300,000
400,000
500,000
600,000
700,000
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012
Potholes Filled by Year (2000-2012)
-
7/28/2019 Potholes in Edmonton
5/19
4
POTHOLES IN EDMONTON
How much does Edmonton spend fixing potholes?
A true accounting of the cost of the pothole problem would consider a number of factors, including:
The cost to fill potholes each year The cost of any preventative maintenance undertaken The cost of any claims paid out The cost of repairs to vehicle damage caused due to potholes
Unfortunately, available data on these factors is limited. Estimates for the cost of fixing a pothole range
from $8.00 per pothole to $25.00 per pothole.
The City of Edmonton does provide costing information for repairing, maintaining and reconstructing
roads:
Crack sealing (roads in excellent condition) $1.20/m2
Microsurfacing (roads in excellent condition) $4.50/m
2
Resurfacing (roads in fair condition) $23.33/m2
Rehabilitation (roads in fair condition) $79.70/m2
Pothole Repairs (poor condition) $78.77/m2
Reconstruction (very poor condition) $209.00/m2
Heres a look at the annual amount budgeted by the City of Edmonton to fill potholes:
$-
$1,000,000
$2,000,000
$3,000,000
$4,000,000
$5,000,000
$6,000,000
$7,000,000
Pothole Budget by Year (1990-2013)
-
7/28/2019 Potholes in Edmonton
6/19
5
POTHOLES IN EDMONTON
Since 1990, the City of Edmonton has budgeted an average of $3.5 million per year just for filling
potholes, for a total of about $85 million. After reaching a peak in 1995, the budget for potholes
dropped to less than $3 million per year until the mid-2000s.
Heres a look at the same data, adjusted for inflation:
Looking at the raw budget numbers, it appears that Edmonton budgeted about the same for the period
1990-1999 as it did for the period 2000-2009. But taking inflation into account, the City actuallybudgeted about $8 million less in the latter period.
$-
$1,000,000
$2,000,000
$3,000,000
$4,000,000
$5,000,000
$6,000,000
$7,000,000
$8,000,000
$9,000,000
Pothole Budget by Year Adjusted for Inflation
(1990-2013)
-
7/28/2019 Potholes in Edmonton
7/19
6
POTHOLES IN EDMONTON
How does Edmonton compare to other Canadian cities?
Edmonton is one of the few cities that tracks the number of potholes it fills each year, and the only one
that makes that data readily available through its Open Data Catalogue.
Using news articles and other publicly available information, we can get a sense of how Edmonton
compares to other major cities in Canada:
Edmonton fills far more potholes each year than any of its counterparts.
40,000
435,000
50,000
180,000200,000
40,000
200,000
$-
$1,000,000
$2,000,000
$3,000,000
$4,000,000
$5,000,000
$6,000,000
-
50,000
100,000
150,000
200,000
250,000
300,000
350,000
400,000
450,000
500,000
Calgary Edmonton Montreal Ottawa Toronto Vancouver Winnipeg
Average Annual Number of Potholes Filled
vs. Average Annual Budget
-
7/28/2019 Potholes in Edmonton
8/19
7
POTHOLES IN EDMONTON
Using this data we can estimate the amount budgeted per pothole:
While it is hard to make true comparisons across cities, due to differences in the accuracy of the data as
well as the processes and methodologies that each follow, this does give some indication of where
Edmonton lies in relation to other major cities in Canada.
$87.50
$8.51
$50.00
$26.67
$20.00
$11.25$7.50
$-
$10.00
$20.00
$30.00
$40.00
$50.00
$60.00
$70.00
$80.00
$90.00
$100.00
Calgary Edmonton Montreal Ottawa Toronto Vancouver Winnipeg
Average Annual Budget/Pothole
-
7/28/2019 Potholes in Edmonton
9/19
8
POTHOLES IN EDMONTON
How many kilometers of road does Edmonton need to maintain?
The City of Edmonton currently maintains more than 4,600 kilometers of roads. Heres a look at the
increases to our road network since 1994:
A measure known as the Pavement Quality Index (PQI) is used to distinguish between roads in poor
condition and those in good condition. A score of 6.5 out of 10 is considered industry standard for
quality.
In 1993, a study found that 29% of Edmontons arterial and collector roads were in poor condition, while
19% of local roads were in poor condition. In 1995, the City attributed a PQI of 5.4 to arterial roads and
5.2 to collector roads. A report in 2007 warned that these values would drop to 5.2 and 4.4 respectively,
unless funding levels increased.
From the approved 2012-2014 Capital Budget:
The Arterial Road Rehabilitation Program approved budget is only 39 per cent of the minimum
$40 million per year required funding levels. The level funding could result in an overall decreasein the Pavement Quality Index (PQI) for arterial roads. As a result of increased investment in
2009-2011, the average PQI for arterial roads is currently 6.1. The reduction in approved funding
for this program could result in an overall decrease in the PQI from 6.1 down to 5.1 over the
course of the 3-year budget program, resulting in PQI ratings equivalent to that of the mid
1990's. This would present as an increase in the number of potholes and the amount of
operational maintenance required.
3900.00
4000.00
4100.00
4200.00
4300.00
4400.00
4500.00
4600.00
4700.00
Length of All Roads Maintained in KM
(Edmonton, 1994-2012)
-
7/28/2019 Potholes in Edmonton
10/19
9
POTHOLES IN EDMONTON
What are the traffic trends in Edmonton that affect potholes?
As traffic is one of the two most important factors in the creation of potholes (the other being water) it
may be useful to know more about traffic.
Heres a look at the number of registered motor vehicles in Edmonton, St. Albert, and Leduc:
Edmonton accounted for roughly 18.9% of all motorized vehicles registered in Alberta in 2012. Tha ts a
small decline from 2004 when the percentage was 19.3%.
One of the best sources of information on driving habits is the Canadian Vehicle Survey, last updated in
2009. Looking at that data, we can see that the number of kilometers traveled each year in Alberta has
increased to nearly 50 billion.
458,799 470,839492,886
524,845554,714 567,745
574,802 585,765602,783
-
100,000
200,000
300,000
400,000
500,000
600,000
700,000
2004 2005 2006 2007 2008 2009 2010 2011 2012
Number of Registered Motor Vehicles
(2004-2012)
EDMONTON ST. ALBERT LEDUC
-
7/28/2019 Potholes in Edmonton
11/19
10
POTHOLES IN EDMONTON
Another factor to consider is the weight of vehicles. While the distance travelled by vehicles in all classes
has gone up 15.3% in Alberta from 2000 to 2009, the largest increase has been in vehicles that weight
more than 4.5 tonnes.
42.140.4
37.039.4 38.7
44.1 45.547.8 47.4
49.7
-
10.0
20.0
30.0
40.0
50.0
60.0
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
BILLIONS
Vehicle-Kilometers in Alberta (Total)
13.2%
56.2%
17.2%
0.0%
10.0%
20.0%
30.0%
40.0%
50.0%
60.0%
Vehicles up to 4.5 tonnes Trucks 4.5 tonnes to 14.9 tonnes Trucks 15 tonnes and over
Increase in Annual Vehicle-Kilometers in Alberta
(2000-2009)
-
7/28/2019 Potholes in Edmonton
12/19
11
POTHOLES IN EDMONTON
How does the weather in Edmonton affect potholes?Heres a look at the amount of precipitation recorded per year at the City Centre Airport:
Heres a look at the difference in extreme temperatures recorded per year:
445
408
375
247
484
519
287
430
272293
244
381 390370
0
100
200
300
400
500
600
1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012
Total Precipitation by Year (mm)
29.1 29.133.5 34.9 33.0 31.2 30.1
35.132.5
35.0 33.531.1 32.5
33.1
-29.2 -27.8
-24.4
-29.5-34.0 -35.4
-33.3-28.3 -29.3
-36.0 -36.5
-27.6 -30.6 -32.1
-50.0
-40.0
-30.0
-20.0
-10.0
0.0
10.0
20.0
30.0
40.0
1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012
Difference in Extreme Temperatures by Year
Max Temp (C) Min Temp (C)
-
7/28/2019 Potholes in Edmonton
13/19
12
POTHOLES IN EDMONTON
It is commonly stated that freeze/thaw cycles contribute to the degradation of road surfaces. Heres a
look at the number of days per winter (October through March) where a temperature increase from
below zero to above zero was preceded by precipitation.
While there does not seem to be a correlation between the number of potholes (remember 2007 was
the worst year on record) and the number of freeze/thaw days, there are other factors to consider. This
data comes from the City Centre Airport, but temperature and precipitation are not uniform around the
city. There could be large variations in precipitation that make potholes more likely to form in one part
of the city versus another.
9
5
4
12
6
3
5
9 9
13
9 9
6
13
0
2
4
6
8
10
12
14
Winter Days of Freeze/Thaw
Preceded by Precipitation
-
7/28/2019 Potholes in Edmonton
14/19
13
POTHOLES IN EDMONTON
Heres a look at the total amount of precipitation per winter:
Heres a look at the number of winter days below and above zero degrees:
75.8
34.6
76.2
126.6
90.6
101.3
57.5
68
53.5
6268
78.5
48.5
103
0
20
40
60
80
100
120
140
Total Precipitation by Winter (mm)
0 20 40 60 80 100 120 140 160 180 200
1999-2000
2000-2001
2001-2002
2002-2003
2003-2004
2004-2005
2005-2006
2006-2007
2007-2008
2008-2009
2009-2010
2010-2011
2011-2012
2012-2013
Number of Winter Days Below & Above Zero
Degrees (Mean)
Below Zero Days Zero & Above Days
-
7/28/2019 Potholes in Edmonton
15/19
14
POTHOLES IN EDMONTON
Heres a look at the temperature extremes by winter:
21.9 23.219.1 17.4
27.124.1
19.0 20.2
25.3 27.1
17.8
23.9
17.720.5
-26.1 -27.8 -29.5-34.0 -35.4
-33.3
-28.3 -29.3
-36.0-33.3
-36.5
-30.6 -32.1-28.6
-40.0
-30.0
-20.0
-10.0
0.0
10.0
20.0
30.0
40.0
Difference in Extreme Temperatures by Winter
Max Temp (C) Min Temp (C)
-
7/28/2019 Potholes in Edmonton
16/19
15
POTHOLES IN EDMONTON
How often do we talk about potholes in Edmonton?
Heres a look at the number of Edmonton Journal articles mentioning potholes from 1989 to March of
2013:
The two years with the most articles, 2007 and 2011, are also the two years with the most potholes
filled. The jump in 1992 may be accounted for by the doubling of the pothole budget that year.
32 35
61
81
59 65 5866
87
59 63 6549
69 68
96
7990
275
118104
89
145
4552
0
50
100
150
200
250
300
Pothole Articles in the Edmonton Journal by
Year (1989 - March 2013)
-
7/28/2019 Potholes in Edmonton
17/19
16
POTHOLES IN EDMONTON
Heres a look at the number of pothole-related tweets posted by Edmontonians from 2009 to 2012.
Unsurprisingly, more tweets are posted in March and April when the snow melts and potholes form and
become visible:
64
281
1078
516
184132 158
104 111 13061 54
0
200
400
600
800
1000
1200
Pothole Tweets by Edmontonians by Month
(2009-2012)
-
7/28/2019 Potholes in Edmonton
18/19
17
POTHOLES IN EDMONTON
What other factors could be considered?
There are many other factors that could be considered when examining Edmontons pothole problem,
including:
Information about snow removal Information about drainage and standing water Information about experiments with materials (asphalt, concrete, polymers, etc.) Details about the construction criteria for roads over time (thickness, etc.) Information about road maintenance programs in addition to pothole filling Further detail about traffic volumes on City streets Further detail about temperature and precipitation in regions of the City Data about utility placement and cutting (manhole covers, etc.) Information about soil Information about the number of buses and bus stops
-
7/28/2019 Potholes in Edmonton
19/19
18
POTHOLES IN EDMONTON
Sourceshttp://en.wikipedia.org/wiki/Pothole
http://www.crrel.usace.army.mil/library/specialreports/SR81-21.pdf
http://www.columbiamissourian.com/m/24523/how-do-potholes-form/
http://www.calgarysun.com/videos/featured/featured-cal/1213592865001/city-plugs-97-pothole-fill-
rate/1525054990001
https://data.edmonton.ca/Transportation/Potholes-Filled/uytp-iqga
http://www.bankofcanada.ca/rates/related/inflation-calculator/
http://www.edmonton.ca/transportation/road_projects/roads-infrastructure.aspx
http://www.transportation.alberta.ca/Content/docType47/Production/vehreg2008.pdf
http://www.transportation.alberta.ca/Content/docType47/Production/vehreg2012.pdf
http://www5.statcan.gc.ca/bsolc/olc-cel/olc-cel?catno=53-223-X&CHROPG=1&lang=eng
http://climate.weatheroffice.gc.ca/climateData/hourlydata_e.html?timeframe=1&Prov=XX&StationID=1
867&Year=2013&Month=4&Day=
http://climate.weatheroffice.gc.ca/climateData/hourlydata_e.html?timeframe=1&Prov=XX&StationID=3
1427&Year=2013&Month=4&Day=
Licensehttp://creativecommons.org/licenses/by-sa/2.5/ca/