Transcript ROUNDABOUT TRAINING HANDOUTS

NEW YORK STATE
DEPARTMENT OF TRANSPORTATION
Roundabouts
Status within
NYSDOT
Roundabouts in New York State
Total Number is at Least 64
* 45 on the state system
* 19 off the state system
46 are single laners
7 are major-minors
11 are 2 laners
No 3 laners yet
No minis currently – had 1 in the state but didn’t make it
more than a month or so… 
New York has at least 90 in design throughout the state
New York Roundabouts – Single Laners
North Haven(01)
single laner that was to be 1 of 2
Rochester
single laner on RIT campus
(03)
Great Neck (03)
single laner that replaced signalized circle
Voorheesville (03) single laner that replaced yield “Y”
Greenwich (04)
single laner that replaced signalized “T”
Ithaca
single laner off state system
(04)
Plattsburgh (04)
single laner that replaced signalized 4-way
Liberty (2)
single laners off Exit 100, I-86
(06)
Cortlandt Manor(06)single laner that replaced signal
Huntington
Rochester
(02)
(05)
single laner used for traffic calming
single laner w/ raised pedestrian crossing
Common Unrealistic Objection – Large Trucks
75’x13’ Modular Home Takes Left at Greenwich, NY Roundabout
…New York Roundabouts – Single Laners
Mt Vernon
(06)
single laner with fountain and music
Mendon
(06)
single laner with center light; hi-speed
Stony Brook, LI(06) single laner on campus roadway
Poughkeepsie (3)(06/08) single laners near Vassar College
Bethlehem
(07)
Bainbridge (07)
single laner that replaced a 3-way stop
single laner just off I-88 exit w/NY 206
Hamburg (4) (07/08) urban single laners made of 100% PCC
Westchester Airport (06) access to local airport
Westhampton Beach (06) oval single laner at former 6 corners
Eastern LI
(07)
local intersection designed by McLean
Colonie Center (07) access to mall from town road
Glens Falls
(07) 5 legs in urban, downtown environment
Glens Falls – 5 leg urban - downtown
…New York Roundabouts – Single Laners
Malta
(08)
single laner for Round Lake Bypass
Cohoes
(08)
single laner at 3 corners
Niagara Falls (07)
single laner on Rainbow Boulevard
Malta (2)
(08)
single laners on Dunning St. for Tech Parks
Buffalo (2)
(08)
single laners that are only 100’ apart
Caledonia
(05)
resigned & restriped traffic circle
Batavia
(09)
single laner @ 33/98
Latham
(09)
Old Wolf @ Old Nisky
Rotterdam
(09)
single laner @ 7/146
Irondequoit (4)(09) single laners (mostly) at end of 590
Chatham
(09)
small single laner
Aurora
(09)
resigned and restriped single lane circle
2 Roundabout Solution Recently Completed
Harlem Road at Kensington Ave and Wehrle Drive
…New York Roundabouts – Major/Minors
Kinderhook (05)
2 laner for SB direction only, 5 legs
Buffalo
Harlem/Cleveland Road
(08)
Corning (2) (03)
access permits for R & D plant
Latham
(02)
resigned & restriped traffic circle
Griffiss
(02)
major-minor done in old air force base
Round Lake (09)
major-minor @ Rt 9/67
Latham Traffic Circle Retrofit - Before
Latham Traffic Circle Retrofit - After
Latham Multi Lane Approach – Before
Alignment, Signing & Striping
Latham Multi Lane Approach – After
Alignment, Signing & Striping
New York Roundabouts – Two Laners
Kingston
(00)
2 laner that replaced traffic circle
Malta (5)
(06)
5 total in a ¾ mile corridor
Johnson City (05) 2 laner & flyover that replaced traffic circle
Slingerlands (4) (07) 4 total in a 1.5 mile section of new hwy
Malta now has 7 in a row… 
New York Roundabouts – In Construction or maybe finished
Colonie
major-minor at Albany-Shaker & Maxwell
Buffalo (2)
major-minor on Outer Harbor project
Brockport
single laner that may be awarded???
…New York Roundabouts – In Final Design
Malta (2)
a single & major-minor for AMD
Monticello
single laner @ 104 off 17B
Mayfield
major-minor @ 29 & 30
East Greenbush
Route 4 @ 151
…New York Roundabouts – In Design
Auburn
railroad right thru center island
Cicero
Onondaga County project
Glenville
Maple @ Glenridge Road
Huntington
(2)
Rt 110 near school for the blind
Roundabouts
Lessons Learned
the Hard Way
Traffic Circle vs. Roundabout
Kingston Traffic Circle Under Construction to become a Roundabout
Kingston Roundabout Striping
If you sign & stripe it like a single lane – SURPRISE!
North Haven on Long Island – Design Vehicle?
North Haven on Long Island – Design Vehicle?
WB-50
North Haven on Long Island – Design Vehicle?
WB-67
WB-50
Rome – Former Griffiss Air Force Base
What’s wrong with the truck apron?
Winter Plowing can still be a challenge
Roundabouts
Policy at NYSDOT
Draft HDM Chapter 26
 Based on FHWA Guide
 Presently 103 pages – should be around 20 when done
 Alterations / additions to FHWA guide:
 Standard left turn arrows on approaches removed
 Both sharks teeth and dashed line used



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Two lane roundabouts striped
Truck aprons required for multi-lane roundabouts
WB-67 is default design vehicle
Lane by lane capacity analysis required
 Critical gap reduced for intersection sight distance
HDM Chapter 26
 Should be released later this year – for 5 years running 
 NYSDOT is still finalizing standards for a few roundabout
topics – primarily: visually impaired accommodations
 NYSDOT now requires that roundabouts be considered
whenever an intersection is being evaluated for capacity
or safety improvements, and if determined feasible than it
SHOULD be NYSDOTs preferred intersection by default
 Many other states already have similar policies
recommending roundabouts…
… more states to follow.
NYSDOT HDM Chapter 5 – Policy as of 8/23/06
FHWA Field Memo – July 10, 2008
Consideration and Implementation of Proven Safety Countermeasures
GUIDANCE STATEMENT:
“Roundabouts are the preferred safety
alternative for a wide range of
intersections. Although they may not be
appropriate in all circumstances,
they should be
considered as an
alternative for all
proposed new
intersections on
Federally-funded
highway projects…”
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Future Concerns
 Funding!
 Funding!
 Funding!
 Oversized Vehicles – especially for the wind farms
 Visually Impaired Pedestrian Accommodation – ADAAG - Liability
 All 2 lane crossings are likely to require some form of
signalization – HAWK or hybrid, RRFB …
 Likely going to make 2 lane roundabouts harder to put in
just based on cost increase: +/- $250K per rbt
 2019 Compliance Date?
Roundabouts
Changes over the
years at NYSDOT
Design Steps and Capacity Analysis
 Design
 Offset Left now preferred over radial
 “Streamlined & simplified” process
 Capacity Analysis
 Was geometric specific (RODEL ONLY)
 Now lane-by-lane (SIDRA & VISSIM)
Note: I will elaborate on capacity tomorrow morning
2000 FHWA Recommendations
Offset Left Now Preferred by
NYSDOT & Other Organizations
Central City Roundabout - Radial
Central City Roundabout – Offset Left
Design Steps
1ST – place 150’
diameter circle at
center of existing
intersection. All
work being done
at this point is with
paint lines – curb
lines are just
offsets from the
paint lines
Design Steps
2nd – copy 150’
diameter circle
parallel around
18’ or so twice –
once for the
travel lane and
another time for
the truck apron
NOTE: later you
will need to
check with
AutoTurn,
AutoTrack or a
similar program
Design Steps
3rd – use a 300’
to 800’ fillet to
tie the center
line to the exit
side of the truck
apron and the
left edge line to
the outside of
the roundabout
– use the same
radius to let
CAD worry
about the taper..
Design Steps
4th – copy the
new center line
over 12’ for your
new right edge
line
Design Steps
5th – use a 90’ to
110’ fillet to tie in
the approach.
Use the same
radius on both
sides – let CAD
take care of the
taper…
RESULT
One leg is done
– you now have
an approach
with geometry
that requires
vehicles to slow
down before the
yield line. This
technique has 2
points of speed
reduction – you
have staged
and staggered
the speed
reduction
The NYSDOT
Roundabout Design Unit
would like to thank everyone
for their attention this
morning…
NYSDOT Roundabout Design Unit
Contact Information
Howard McCulloch, Richard Schell, PE
Michael Houlihan, Greg Bailey
and Tom Kligerman, PE
Roundabout Design Unit
50 Wolf Road, POD 24
Albany, New York 12232
Tel: (518) 485-7503
Fax: (518) 457-2916
E-mail: [email protected]