1/3/2016
Revision 1
Cleaning
the “Dirty 17” Burlington, VT One-a-Year Pedestrian Injury
Intersections to About One a Decade Average with
Roundabouts--Opportunities and Costs
Summary
As
analyzed here, cleansing 15 of the “dirty 17” Burlington
intersections averaging one pedestrian injury a year occurs by
converting them to roundabouts. After conversion pedestrian crashes
would drop from15 pedestrian injuries a year now to one or two a
year. The 90% reduction in pedestrian crashes prediction is based on
single lane roundabout research and the recent tabulation of 52 years
of Vermont downtown/town center roundabouts history which recorded
just a single non-serious pedestrian injury. Two of the “dirty 17”
intersections—one during the 2011-2014 data collected in the Walk
Bike Master Plan study now under way and one in 1998—recorded a
pedestrian fatality. The 2015 measure of the value of a life saved
used by the Federal Highway Administration is $9.4 million. A recent
value of a highway injury used in a American Automobile Association
study (Cambridge Systematics) was $126,000.
Introduction
The
Burlington Walk Bike Master Plan identifies 17 intersections
averaging one (0.9) pedestrian injuries per year for the four years
2011-2014. Just now safety performance data on of five downtown
Vermont roundabouts found one pedestrian injury (not serious) over a
span of 52 years of roundabout operation history through late 2015.
The Burlington “dirty 17” record includes a fatal injury and at
least one critically injury. Since roundabout research indicates a
90% reduction in pedestrian injuries at single lane roundabouts
compared to signs and signals, “cleaning” the “dirty 17” in
Burlington with single lane roundabouts reduces frequency of
pedestrian crashes to one per decade and decreases injury severity as
well. Of the 17 intersections all but perhaps two—requiring two
lane roundabouts—are single lane roundabout candidates. Note,
single lane roundabouts research conclusively finds single lane
roundabouts deceasing serious and fatal car occupant injuries by 90%,
and research finds single lane roundabouts for cyclists reaches
towards the 90% reduction of injuries if a separate path or ramp
off/on to join with pedestrians for crossings is provided.
Vermont's
Montpelier Keck Circle first roundabout in the northeast (19th
in the U.S.) in 1995 and Grand Union Roundabout in Manchester Center
in 1997 by chance are two of the earliest downtown/town center
roundabouts in the U.S. and Canada. Now along with two more
roundabouts in Manchester Center and the Main Street Roundabout in
Middlebury, this group of five become first to reach 52 years of
service with both significant volumes of pedestrians but also an
ongoing tabulation of pedestrian accident data. The Vermont downtown
roundabout performance does not come as a total surprise as
international research finds about a 90% reduction in pedestrian
injuries at single lane roundabouts like Vermont's. Still, the
Vermont downtown roundabout safety performance of one minor
pedestrian injury in 52 years stands in sharp relief opposite to the
Burlington “dirty 17” recording one pedestrian crash per year
2011-2014 with one fatality and at least one critical injury.
The
question can be asked “what if” the pedestrian “dirty 17”
intersections in Burlington were converted to a roundabout, what
would be the costs? Using the rule of thumb of a 90% reduction of
pedestrian injuries of roundabouts over signed or signalized
intersections, the 17 injuries a year at the Burlington intersection
would drop to less than two per year. The U.S. sinking from first to
19th
in highway safety with over 40% of the 30,000 annual deaths prevented
by reaching top nations in highway safety, this analysis is far more
than a theoretical exercise. Further in the last decade as more walk
and bike--”healthy transportation”--walk and bike fatalities have
plateaued and even increased, and have become a higher proportion of
overall highway fatalities as both modes vulnerability in crashes
with vehicles is obvious and practically impossible to alter in a
significant way.
The
following analysis makes these assumptions;
Any
consideration of roundabouts at a high accident location—like the
“dirty 17”-- requires a full engineering study involving an
experienced roundabout designer. (Vermont remains one of the rare
states where almost all the long time roundabout practitioners have
either presented workshops in the State or done design work here—in
some cases both.)
At
some point—the sooner the better--high accident intersections in
Burlington will be evaluated for roundabout or other major safety
upgrade, and a list of intersections will be prioritized—ditto for
Chittenden County which lacks a single safe roundabout intersection
on a busy public street.
The
cost assumptions here are that the projects will be done without use
of federal funding. Costs would be roughly 75% higher with the
involvement of federal funds. Where federal funds are known to be
involved (Shelburne Street Roundabout and Champlain Parkway
intersections) a “federal” estimate is provided.
Mini-roundabouts
can be built with very low costs. A high-end figure of $50,000 will
be used in these estimates.
All
estimates are those of the author based on experience—they are
“ballpark” only and can only be refined by engineering studies.
All
intersections would include separate walk and bike treatment or,
mostly likely given constraints, off/on ramping to give a cyclist
the choice of “taking the circulating travelway” or “ramping
off” onto shared pedestrian space, proceeding across crosswalk(s)
before “ramping on” to the street to continue on (this is the
Shelbune Street Roundabout design at Shelburne/Locust/So. Willard
set for construction in 2021, possibly earlier).
Estimated
Total Costs for Roundabouts
The
total cost estimates provided below of $39 million for 15 of the
intersections exclude the possible treatments which may include a
roundabout for the North Street/Murray Street node and the “area”
identified in the Walk Bike Master Plan between Intervale Road and
Hill Street node. The estimates for three of the intersections are
for mini-roundabouts with an estimated cost of $50,000 ear. Note
there are 75 signalized intersections in Burlngton and 11 conversions
to roundabouts are contained in the estimates here. The North Avenue
Corridor Plan includes conversion of another three signals to
roundabouts. The $39 million cost for 15 roundabouts compares to the
$43 million current cost estimate for the Champlain Parkway. Using a
cost factor of 1.75 for federally built roundabouts (other than the
three given in federal estimates, that is Pine/Locust, Pine/Lakeside
and the Rotary Roundabout) the total for the 15 roundabouts is $60
million.
Roundabouts
tend to score very well against alternative transportation
investments in benefit cost analyses in great part because of
substantial reductions in crashes (50 percent), injuries and injury
severity, and low maintenance costs. In addition, roundabouts cut
fuel consumption by about a third compared to signals, pollution and
global warming gases by a similar amount compared to signal, sharply
reduce delay for all users and provide 50 to 100% greater capacity
for cars. Obviously the roundabout features a higher level of scenic
quality.
Outline
of Possible Roundabout Treatments for Burlington's 17 High
Pedestrian Injury intersections
Note again the following 17
intersections evaluation proceeds without consideration to priority
or connection with other planned City intersections except for the
Parkway intersections of Pine/Locust, Pine/Lakeside and the
“Shelburne Street Roundabout” (Shelburne/Locust/South
Willard)--all currently scheduled for funding in committed projects
and therefore are considered fully funded.
North
Winooski/South Winooski (North Winooski/Pearl), South
Winooski/Cherry, South Winooski/Bank, South Winooski College, and
South Winooski/Main)
These five intersections represent the
only “corridor” where all show up on the high pedestrian crash
list. This corridor and Battery Street are the only two-way
north/south through streets serving the Marketplace. The Burlington
Town Center plan to connect Pine Street again from Pearl Street
southward through the Town Center would move a significant amount of
vehicle traffic off South Winooski (and some off Battery Streets).
Roundabout treatments need to be part of a corridor (Pearl to Main)
approach of five roundabouts developed together as a package over a
period of time as each relates directly to the performance of
adjacent roundabouts. The improved connectivity from a Pine Street
re-connection would result in traffic reduction on South Winooski
would perhaps change some of the challenges for roundabouts along
South Winooski intersections.
North
Winooski/Pearl
Treatment:
This intersection presents the most difficult challenge along South
Winooski. Only the southwest quadrant presents the possibility of a
roundabout. Roundabouts do can be off center in an intersection.
Still a major traffic calming treatment is required to reduce
pressure on the Church/Pearl mid-block crossing. Cost:
$3 million (if feasible).
South
Winooski/Cherry
Treatment:
A single lane roundabout can be fashioned with use of institutional
right-of-way to the east and possibility a slight amount from the
Rite Aid site (Rite Aide gets the benefit of a possible direct entry
onto the roundabout). Also the resolution of revamping North
Winooski/Pearl and South Winooski/Bank ties directly to design for
this intersection. Estimated
cost:
$3 million
South
Winooski/Bank Street
Treatment:
Utilizing the likely moving or closure of both gas stations at the
west corners of the intersections as high level economic value uses
take over these two sites, space can be reserved allowing an easy
installation of a one lane roundabout which would also benefit the
developments occupying the space of the former gas stations.
Estimated
cost:
$3 million
South
Winooski/College
Treatment:
Right-of-way restrictions from three of four corner buildings (also
narrowest width between east and west buildings on South Winooski
between Pearl and Main) only allow consideration of a
mini-roundabout. Again, a mini-roundabout needs to be part of an
overall set of intersection treatments from Pearl to Main. Since
even with current traffic levels a “road diet” has been
suggested, such a change would augur well for a mini-roundabout
feasibility. Estimated
cost:
$0.5 million.
South
Winooski/Main
Treatment:
Likely the only intersection requiring a two-lane roundabout with
pedestrian actuated signals designed primarily for those with severe
visual disability. Also the most expensive roundabout. Estimated
cost:
$6.0 million
2.
Shelburne
Street “Rotary” at Locust/South Willard
Treatment:
“Shelburne Street Roundabout”, single lane, 100% federally funded
safety project scheduled to be completed sometime during 2018-2021.
Chittenden County Regional Planning Commission (CCRPC)
“Transportation Improvement Program FY 2014-2017.” Total
Estimated cost:
$2.9 million (100% of funding from federal sources already allocated)
Archibald/Intervale Ave
Treatment:
This four-way stop intersection clearly lends itself to a
mini-roundabout treatment. The skewed character of this intersection
does present some design challenges. Estimated
cost:
$50,000
Riverside—Intervale Rd to
Hillside Ave
Treatment:
This “area” with four pedestrian injuries may be better served
by traffic calming and other related treatments. A serious bike
injury—typical of multi-use paths at signals—occurred at the
Riverside/Intervale Rd intersection as a cyclist crashed into a car
with a green light entering Intervale Rd from Riverside—establishing
a barrier/buffer to force cyclists to come to a stop or a roundabout
for the intersection might be possible. Treatments to be determined
after an engineering study. Estimated
cost:
No estimate at this time.
5.
North
Street at Murray
Treatment:
The Walk Bike Master Plan suggestion for this “area” is a
“shared space” concept. Such a design could very well include a
circular paving area at Murray where vehicles would enter/exit Murray
in a “roundabout manner.” This approach has been used in
European applications. Estimated
cost:
No regular roundabout to be used.
6.
North
Winooski/North
Treatment:
This fully signalized intersection with pedestrian actuation can be
covered to a mini-roundabout. With four commercial/retail buildings
on each corner the intersection does generate a significant amount of
foot traffic. Estimated
cost:
$50,000
7.
Loomis/North
Prospect
Treatment:
This two-way stop control intersection can be converted into a
mini-roundabout which will traffic calm Prospect, a busy minor
arterial street. Estimated
cost:
$50,000
Main/St. Paul
Treatment:
This intersection adjacent to City Hall Park was the site of a high
speed chase involving police and the miscreant driver whose vehicle
T-boned a vehicle driven by Kaye Borneman, a Dealer.com employee.
“Normal” roundabouts with central islands virtually eliminate the
T-bone crash—and roundabouts when installed in downtowns and town
centers also make high speed chases difficult and interception by law
enforcement easy at the nearest roundabout. With the availability of
some public land a normal roundabout may be feasible at this
intersection or if not feasible a mini-roundabout is indicated.
Estimated
cost:
$3 million
9.
Pine/Lakeside
Ave
Treatment:
This signal intersection along the Parkway route will experience
considerable increase in traffic volume with the Parkway completed as
now designed. With a coffee shop, Department of Public Works main
office facility and a gas/convenience store bordering, some design
challenges exist. But relatively open area at the gas/convenience
store site—perhaps it will have direct roundabout entry--makes it
very likely a workable roundabout design is feasible. While the City
is spending about $420,000 of local funds currently for a signal
upgrade, the City costs for a roundabout as part of the Parkway would
be 2% of an estimated total cost of $5 million as a federally funded
project or $100,000.
Estimated
cost:
$5 million
10.
Colchester/Barrett
Treatment:
This intersection is part of a complex of streets requiring a larger
design solution—very likely at least two single lane roundabouts.
Colchester/Barrett and Colchester/Riverside Ave intersections are
closely related, and Riverside also has a spur easterly enabling
vehicles to cross between it and Barrett. Overall the overhaul of
these two intersections along with Mill Street, a T intersection
between the Colchester/Riverside/Barrett connections to the north and
a few feet from the bridge to Winooski, may lead to making Mill
Street one-way westerly with an outlet onto Barrett. Roundabouts
would enable such a circulation solution. With likely retaining
walls and other structural needs to accommodate a satisfactory
engineering solution, an estimated cost may well climb to about $8
million. For purposes here, $4 million will be allocated as the cost
responsibility for Colchester/Barrett. Estimated
cost:
$4 million
11.
Colchester/East
Ave
Treatment:
Colchester/East Ave presents perhaps the easiest normal roundabout
opportunity with publicly owned land on three quadrants and no
right-of-way constrictions on on the west side of Colchester Ave.
Estimated
cost:
$2 million
12.
Pine/Locust
Treatment:
A critical injury at this intersection occurred a few months after
installing a Rectangular Rapid Flashing Beacon (RRFB) for crossing
Pine Street only. A single lane roundabout is feasible at this
intersection because of the availability of right-of-way on the west
side of Pine from property owned by BED. This intersection would
likely be upgraded as part do a “corridor of roundabouts”
including Pine/Howard and Pine/Lakeside intersections converted to
roundabouts (up to 10 or more roundabouts conceivable along the
Parkway). The cost of this intersection for the City will be
estimated at 2% of $3 million (federal project cost) as part of the
Parkway project, or $60,000. Estimated
cost:
$3 million
13.
Shelburne/Home
Treatment:
This intersection definitely requires a two-lane roundabout and
along with South Winooski/Main (possibly) represent the only two
multi-lane roundabouts among the 17 intersections. Still,
Shelburne/Home will experience some decline with the opening of part
or all of the Parkway, conceivably decreasing the traffic to the
point a single lane roundabout suffices. Linda Ente during a trip
work at Price Chopper was killed on the crosswalk at this
intersection in 1998. Estimated
cost:
$4 million
Tony Redington
@TonyRVT08
TonyRVT.blogspot.com
