|
FORCED
TURN ISLANDS, BARRIERS & CHANNELIZATION
Make
sure problems do not move elsewhere.
Temporary installation is highly recommended for initial evaluation.
These are
traffic islands or curbs specifically designed to prevent traffic
from making certain movements at an intersection or to force the
traffic into specific patterns. They are sometimes referred to
as "Pork Chops" or right-turn islands.
Care should be taken to evaluate the effects of diverted traffic
on adjacent streets. Problems could be simply transferred from
one location to another.
Access to residences may also be adversely affected so coordination
with neighborhoods is important.
|
Temporary
Installation
Temp Island Installation
|
Permanent
Installation
Baldwin Park, CA |
PROS
1.
Potential to reduce traffic speed.
2. Reduces traffic volumes.
3. Can be used to reduce cut-through traffic.
4. Self-enforcing.
5. Landscaping possible.
|
CONS
1.
May reduce access for emergency vehicles.
2. Diversion to longer routes may cause inconvenience
to and be opposed by affected residents.
3. Care needed if placed on transit routes.
4. May transfer problems elsewhere.
5. Need to allow bicycle access.
|
Summary
of Effectiveness
|
Volume
Reduction
|
Yes
|
|
Speed
Reduction
|
Likely
|
|
Safety
Improvement
|
Possible
|
|
-
|
-
|
|
Streets
to Use On – Collector, Local
|
Local/Collector
|
|
Use
on Bus Route
|
Check
Routes
|
|
Use
with Curbs and Gutters
|
Yes
|
|
Spot
or Area-wide Use
|
Spot
|
|
-
|
-
|
|
Emergency
Service Access Issues
|
Possible
|
|
Impacts
on Arterials
|
Possible
|
|
Change
in % Trucks
|
Unknown
|
|
Environmental
Changes
|
Unknown
|
|
-
|
-
|
|
Dependence
on Enforcement
|
No
|
|
Level
of Violation
|
Self-Enforced
|
|
-
|
-
|
|
Aesthetics
and Landscaping
|
Possible
|
|
