Status of Roundabouts in North America, 2017 Edition ...roundabouts.kittelson.com/pdf/Rodegerdts -...
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WA MT ME ND SD WY WI ID VT MN OR NH IA MA NE NY PA CT RI NJ IN NV UT CA OH IL DE WV MD CO KY KS VA MO AZ OK NC TN TX NM AL MS GA SC AR LA FL MI AK HI Roundabouts 2015 Roundabouts per State 0 1 - 25 26 - 50 51 - 100 101 - 200 201 - 400 WA MT ME ND SD WY WI ID VT MN OR NH IA MA NE NY PA CT RI NJ IN NV UT CA OH IL DE WV MD CO KY KS VA MO AZ OK NC TN TX NM AL MS GA SC AR LA FL MI AK HI Roundabouts 1995 Roundabouts per State 0 1 - 25 26 - 50 51 - 100 101 - 200 201 - 400 WA MT ME ND SD WY WI ID VT MN OR NH IA MA NE NY PA CT RI NJ IN NV UT CA OH IL DE WV MD CO KY KS VA MO AZ OK NC TN TX NM AL MS GA SC AR LA FL MI AK HI Roundabouts 2000 Roundabouts per State 0 1 - 25 26 - 50 51 - 100 101 - 200 201 - 400 WA MT ME ND SD WY WI ID VT MN OR NH IA MA NE NY PA CT RI NJ IN NV UT CA OH IL DE WV MD CO KY KS VA MO AZ OK NC TN TX NM AL MS GA SC AR LA FL MI AK HI Roundabouts 2005 Roundabouts per State 0 1 - 25 26 - 50 51 - 100 101 - 200 201 - 400 WA MT ME ND SD WY WI ID VT MN OR NH IA MA NE NY PA CT RI NJ IN NV UT CA OH IL DE WV MD CO KY KS VA MO AZ OK NC TN TX NM AL MS GA SC AR LA FL MI AK HI Roundabouts 2010 Roundabouts per State 0 1 - 25 26 - 50 51 - 100 101 - 200 201 - 400 WA MT ME ND SD WY WI ID VT MN OR NH IA MA NE NY PA CT RI NJ IN NV UT CA OH IL DE WV MD CO KY KS VA MO AZ OK NC TN TX NM AL MS GA SC AR LA FL MI AK HI Roundabouts All Roundabouts per State 0 1 - 25 26 - 50 51 - 100 101 - 200 201 - 400 Roundabouts 201 - 400 WA MT ME ND SD WY WI ID VT MN OR NH IA MA NE NY PA CT RI NJ IN NV UT CA OH IL DE WV MD CO KY KS VA MO AZ OK NC TN TX NM AL MS GA SC AR LA FL MI HI 1990 Roundabouts per State 0 1 - 25 26 - 50 51 - 100 101 - 200 AK AK HI All Roundabouts per County 0 1-4 5-11 12-19 20-30 31-106 Status of Roundabouts in North America, 2017 Edition A Snapshot of the Online Database at roundabouts.kittelson.com Maintained voluntarily on behalf of the TRB Committee on Roundabouts New Website – Please Help Us Keep This Database Current! Data sources: Everyone (Thank you!) Database programming: Ian Cameron Quality control team: Lee Rodegerdts, Pete Jenior, Matt Kittelson, Scott Beaird Analysis: Lee Rodegerdts GIS graphics: Jon Sommerville Poster layout: Ralph Bentley Growth over Time Known Roundabouts in the U.S. Why No Maps of Canada This Time? • Database is known to be very incomplete (158 sites) • At least 400 roundabouts believed to exist, but few additions to database since 2014 – your help is needed! Estimated U.S. roundabouts through 2016: 4,200 Number of Approaches Analysis and Methodology By State By County Lane Type 1990 2015 1995 2010 2000 2005 Previous Control Methods and Assumptions • Data pulled April 15, 2017 • Other circular intersections excluded • Current database compared to what was known in 2014, 2011, 2008, and 2003 to estimate undercounting • Total estimated unknown sites in 2016: 29% (40% in 2013) • Unknown sites are distributed over multiple years, biased towards most recent years TRANSPORTATION RESEARCH BOARD 5th International Conference on Roundabouts May 8-10, 2017, Green Bay, Wisconsin Presented by Lee A. Rodegerdts, PE [email protected] 2 approaches 0.8% 4 approaches 63.8% 3 approaches 32.6% 5–8 approaches 2.9% Mini 1% Mullane 28% Single Lane 70% All-Way Stop 3.4% None (new) 22.2% One-/Two- Way Stop 15.4% Other 1.0% Signal 4.2% Unknown 53.7% Credits– 0 50 100 150 200 250 300 350 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Roundabouts per Year Known or Estimated Year Assumed Unknown Site Annual 0 500 1000 1500 2000 2500 3000 3500 4000 4500 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Cumulative Roundabouts Known or Estimated Year Assumed Unknown Site Cumulative roundabouts.kittelson.com
Transcript of Status of Roundabouts in North America, 2017 Edition ...roundabouts.kittelson.com/pdf/Rodegerdts -...
WA
MTME
ND
SD
WY
WI
IDVTMNOR
NH
IA
MA
NE
NY
PA
CT RI
NJ
INNV
UTCA
OHIL
DE
WV MDCO
KYKS VA
MO
AZ OK
NCTN
TX
NM
ALMSGA
SCAR
LA
FL
MI
AK
HIRoundabouts
2015
Roundabouts per State01 - 2526 - 5051 - 100101 - 200201 - 400
WA
MTME
ND
SD
WY
WI
IDVTMNOR
NH
IA
MA
NE
NY
PA
CT RI
NJ
INNV
UTCA
OHIL
DE
WV MDCO
KYKS VA
MO
AZ OK
NCTN
TX
NM
ALMSGA
SCAR
LA
FL
MI
AK
HIRoundabouts
1995
Roundabouts per State01 - 2526 - 5051 - 100101 - 200201 - 400
WA
MTME
ND
SD
WY
WI
IDVTMNOR
NH
IA
MA
NE
NY
PA
CT RI
NJ
INNV
UTCA
OHIL
DE
WV MDCO
KYKS VA
MO
AZ OK
NCTN
TX
NM
ALMSGA
SCAR
LA
FL
MI
AK
HIRoundabouts
2000
Roundabouts per State01 - 2526 - 5051 - 100101 - 200201 - 400
WA
MTME
ND
SD
WY
WI
IDVTMNOR
NH
IA
MA
NE
NY
PA
CT RI
NJ
INNV
UTCA
OHIL
DE
WV MDCO
KYKS VA
MO
AZ OK
NCTN
TX
NM
ALMSGA
SCAR
LA
FL
MI
AK
HIRoundabouts
2005
Roundabouts per State01 - 2526 - 5051 - 100101 - 200201 - 400
WA
MTME
ND
SD
WY
WI
IDVTMNOR
NH
IA
MA
NE
NY
PA
CT RI
NJ
INNV
UTCA
OHIL
DE
WV MDCO
KYKS VA
MO
AZ OK
NCTN
TX
NM
ALMSGA
SCAR
LA
FL
MI
AK
HIRoundabouts
2010
Roundabouts per State01 - 2526 - 5051 - 100101 - 200201 - 400
WA
MTME
ND
SD
WY
WI
IDVTMNOR
NH
IA
MA
NE
NY
PA
CT RI
NJ
INNV
UTCA
OHIL
DE
WV MDCO
KYKS VA
MO
AZ OK
NCTN
TX
NM
ALMSGA
SCAR
LA
FL
MI
AK
HIRoundabouts
All
Roundabouts per State01 - 2526 - 5051 - 100101 - 200201 - 400
Roundabouts201 - 400
WA
MTME
ND
SD
WY
WI
IDVTMNOR
NH
IA
MA
NE
NY
PA
CT RI
NJ
INNV
UTCA
OHIL
DE
WV MDCO
KYKS VA
MO
AZ OK
NCTN
TX
NM
ALMSGA
SCAR
LA
FL
MI
HI 1990
Roundabouts per State01 - 2526 - 5051 - 100101 - 200
AK
AK
HI
All
Roundabouts per County01-45-1112-1920-3031-106
Status of Roundabouts in North America, 2017 EditionA Snapshot of the Online Database at roundabouts.kittelson.comMaintained voluntarily on behalf of the TRB Committee on Roundabouts
New Website – Please Help Us Keep This Database Current!
Data sources: Everyone (Thank you!)Database programming: Ian CameronQuality control team: Lee Rodegerdts, Pete Jenior, Matt Kittelson, Scott BeairdAnalysis: Lee RodegerdtsGIS graphics: Jon SommervillePoster layout: Ralph Bentley
Growth over Time
Known Roundabouts in the U.S.
Why No Maps of Canada This Time?• Database is known to be very incomplete (158 sites)• At least 400 roundabouts believed to exist, but few additions
to database since 2014 – your help is needed!
Estimated U.S. roundabouts
through 2016: 4,200
Number of Approaches
Analysis and Methodology
By State
By County
Lane Type
1990
20151995
2010
2000
2005
Previous Control Methods and Assumptions• Data pulled April 15, 2017
• Other circular intersections excluded
• Current database compared to what was known in 2014, 2011, 2008, and 2003 to estimate undercounting
• Total estimated unknown sites in 2016: 29% (40% in 2013)
• Unknown sites are distributed over multiple years, biased towards most recent years
TRANSPORTATION RESEARCH BOARD5th International Conference on RoundaboutsMay 8-10, 2017, Green Bay, Wisconsin
Presented byLee A. Rodegerdts, PE
2approaches
0.8%
4approaches
63.8%
3approaches
32.6%
5–8approaches
2.9%
Mini1%
Multilane28%
Single Lane70%
All-Way Stop3.4%
None (new)22.2%
One-/Two-Way Stop
15.4%
Other1.0% Signal
4.2%
Unknown53.7%
Credits–
0
50
100
150
200
250
300
350
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
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2010
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2015
2016
Roun
dabo
uts
per Y
ear
Known or Estimated Year Assumed Unknown Site
Annual
0
500
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4500
1990
1991
1992
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2009
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2012
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2015
2016
Cum
ulat
ive
Roun
dabo
uts
Known or Estimated Year Assumed Unknown Site
Cumulative
roundabouts.kittelson.com
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