road diets and roundabouts paul zykofsky, aicp local government commission sacramento, ca
TRANSCRIPT
Road Diets and Roundabouts
Paul Zykofsky, AICPLocal Government Commission
Sacramento, CA
“Classic Road Diet”
San Antonio TXSan Antonio TX
4 to 3 lanes 4 to 3 lanes
Road diets: reclaim street space for other usesRoad diets: reclaim street space for other uses
On-street parkingOn-street parking MedianMedian
Center Turn-LaneCenter Turn-Lane
Bike LanesBike Lanes
Seattle WASeattle WA
X
3 crash types can be reduced by going3 crash types can be reduced by goingfrom 4 to 3 lanes: 1 – rear endersfrom 4 to 3 lanes: 1 – rear enders
Road Diets and Traffic OperationsRoad Diets and Traffic Operations
X
3 crash types can be reduced by going3 crash types can be reduced by goingfrom 4 to 3 lanes: 2 – side swipesfrom 4 to 3 lanes: 2 – side swipes
Road Diets and Traffic OperationsRoad Diets and Traffic Operations
X
3 crash types can be reduced by going3 crash types can be reduced by goingfrom 4 to 3 lanes: 3 – left turn/broadsidefrom 4 to 3 lanes: 3 – left turn/broadside
Road Diets and Traffic OperationsRoad Diets and Traffic Operations
Road Diets in Seattle(4 to 3 lanes)
Roadway Date ADT ADT Collision
Location Change Before After Reduction
Greenwood Ave N
N 80th St to N 50th
N 45th Street
Wallingford Area
8th Ave NW
Ballard Area
Martin Luther King Jr W
North of I 90
Dexter Ave N
Queen Ann Area
24th Ave NW
NW 85th to NW 65thOct-95 9727 9754
14 to 10 28%
Jun-91 13606 1494919 to 16
59%
Jan-94 12336 1316115 to 6 60%
Jan-94 10549 1185818 to 7 61%
Dec-72 19421 2027445 to 23
49%
Apr-95 11872 1242724 to 10
58%
Benefits of road diets for bicyclists and pedestrians? Provide space to add bicycle lanes Reduce crossing distance Eliminate or reduce “multiple threat” crash types Install crossing island to cross in 2 simple steps Reduce top end travel speeds Buffer sidewalk from travel lanes (parking or
bike lane) Reclaim street space for “higher and better use”
than moving peak hour traffic
BeforeBefore
Charlotte NCCharlotte NC
BeforeAfterAfter
Reclaiming road space creates room for Reclaiming road space creates room for bicycle lanes and pedestrian islandsbicycle lanes and pedestrian islandsCharlotte NCCharlotte NC
Case study: Edgewater Drive Resurfacing Project (Orlando, FL) • $589,000 project scheduled in FDOT 5-year work plan
• FDOT open to 3-lane option if City takes over jurisdiction
• Changes must be accepted by neighborhood and business associations; before/after studies
ConceptBefore
Reality: Before
Reality: After
Before/after studies: 1. Crash rate
12.6
8.4
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0C
rash
Rate
(p
er
MV
M)
Before After
1 crash every 1 crash every 2.5 days2.5 days
34% Reduction
(146 per yr)(146 per yr)
1 crash every 1 crash every 4.2 days4.2 days
(87 per yr)(87 per yr)
3.6
1.2
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Inju
ry R
ate
(p
er
MV
M)
Before After
68% Reduction
1 injury every 1 injury every 9 days9 days
(41 per yr)(41 per yr) 1 injury every 1 injury every 30 days30 days
(12 per yr)(12 per yr)
Before/after studies: 2. Injury rate
15.7%
7.5%9.8% 8.9%
29.5%
19.6%
0.0%
5.0%
10.0%
15.0%
20.0%
25.0%
30.0%
35.0%P
erc
en
t o
f V
eh
icle
s T
rav
eli
ng
ov
er
36
MP
H
Before AfterBefore BeforeAfter
North End Middle South End
After
Before/after studies: 3. Speeding analysis
20,50018,100
0
5,000
10,000
15,000
20,000
25,000
Veh
icle
s p
er
Day
Before After
Now21,000+
Before/after studies: 4. Traffic volumes
29%
41%
0%
5%
10%
15%
20%
25%
30%
35%
40%
45%
Park
ing
Uti
lizati
on
Perc
en
tag
e
Before After
Before/after studies: 5. On-street parking utilization
2,136
2,632
0
500
1000
1500
2000
2500
3000
Nu
mb
er
of
Ped
estr
ian
s
Before After
23% Increase
Before/after studies: 6. Pedestrian volumes
375
486
0
100
200
300
400
500
600
Nu
mb
er
of
Bic
ycle
s
Before After
30% Increase
Before/after studies: 7. Bicyclist volumes
Road Diet — BeforeRoad Diet — Before Pottstown, PAPottstown, PA
Road Diet — AfterRoad Diet — After Pottstown, PAPottstown, PA
There’s potential on one-way streets too:There’s potential on one-way streets too:Is this street operating at capacity?Is this street operating at capacity?
Boise IDBoise ID
Road Diet on one-way street: This area was recaptured Road Diet on one-way street: This area was recaptured from a 4from a 4thth travel lane; the street took on a whole new life travel lane; the street took on a whole new life
Portland ORPortland OR
La Jolla Boulevard, Bird Rock, San Diego, California Before
68 Feet
La Jolla Boulevard, Bird Rock, San Diego, California After
14 Feet
La Jolla Boulevard, Bird Rock, San Diego After
La Jolla Boulevard, Bird Rock, San Diego After
RoundaboutsBenefits:Injuries and crashes reduced 90%30% more traffic capacityGateway entryPedestrian-friendlyLow traffic speedsReduced noiseReduced emissionsReduced maintenanceBusiness-friendly
Roundabout design characteristics
Slow speed entry with yield
Slow speed exit
Truck apron
Splitter island
Crosswalk 1 car length back
Lots of deflection for slow speeds throughout
Separated sidewalk to direct peds to crosswalks
Bend OR
Roundabouts are safer
32 vehicle-to-vehicle conflicts24 vehicle-to-pedestrian conflicts
8 vehicle-to-vehicle conflicts8 vehicle-to-pedestrian conflicts
“Results of this study indicate that converting conventional intersections from stop sign or traffic signal control can produce substantial reductions in motor vehicle crashes.”
March 2000 Study by theInsurance Institute for Highway Safety
Before
One pedestrian fatality per year
Bradenton Beach, FL, Intersection of State Routes 684 and 789
After
Zero pedestrian fatalities in over 8 years
Roundabouts and Pedestrians
18 mph
18 mph
Grand Junction, Colorado
14 feet
Sacramento, CA West River Drive and Orchard Lane
Sacramento, CA West River Drive and Orchard Lane
Roundabouts and Bicyclists
Montpelier, VT
University Place, WA
Davis, CA
Roundabouts, Trucks and Fire Departments
Petaluma, CA — Roundabout at Corona Road and Sonoma Mountain Parkway
Petaluma, CA — Roundabout at Corona Road and Sonoma Mountain Parkway
Fire Station #2, 1001 N. McDowell Blvd.Roundabout
Petaluma, CA — Roundabout at Corona Road and Sonoma Mountain Parkway
Mountable Curb for large trucks, emergency responders
Mountable Curb can be used by large trucks, emergency responders
Fort Pierce, FL
Roundabout problems for blind pedestrians:Roundabout problems for blind pedestrians:
• Circulating traffic masks the sound cues the blind use to identify gaps Circulating traffic masks the sound cues the blind use to identify gaps and masks the sound of yielding vehiclesand masks the sound of yielding vehicles
• Tangential circulating roadway, tangential exit => high speed (worse at Tangential circulating roadway, tangential exit => high speed (worse at 2-lane roundabouts)2-lane roundabouts)
Towson MD 8-50