politics and speed zoning in texas
DESCRIPTION
Politics and Speed Zoning in Texas. Aren Cambre ENCE 7391 9-22-04. Agenda. Speed Zoning Basics Texas Statutes Texas Administrative Code (Rules) Flowcharts. Speed Zoning Basics. Key concept: 85 th percentile speed Separates “reasonable” from “unsafe” - PowerPoint PPT PresentationTRANSCRIPT
Politics and Speed Zoning in Texas
Aren CambreENCE 7391
9-22-04
Agenda
• Speed Zoning Basics• Texas Statutes• Texas Administrative Code (Rules)• Flowcharts
Speed Zoning Basics
• Key concept: 85th percentile speed
• Separates “reasonable” from “unsafe”
• Speed limits usually should be 85th percentile speed
Best Practice Speed Zoning
• Measurement• Analysis• Set the limit
Start
Crash rate?All others Unusually high
Other measuresavailable
Other correctivemeasures inadequate
Finish
Available corrective
measures?
Sometimes lower bound is “50th percentile rounded up”
Set speed limit between 67th and
85th percentile speed (each
rounded to nearest 5 MPH)
Research crash causes
Set Speed Limit at 85th percentile
speed (rounded to nearest 5 MPH)
Measure 85th Percentile Speed
Correct problems (striping, road configuration,
signage, signal timing, pedestrian limitations, etc.)
Reality
• Lots of political interference– Rules– Statutes– Loopholes
Texas Statutes
• Statutes are laws passed by Texas Legislature
• Several statutes affect speed limits and speed zoning
• All in Transportation Code
Two Key Statutes
• § 545.351. MAXIMUM SPEED REQUIREMENT– “Reasonable and prudent”
• § 545.352. PRIMA FACIE SPEED LIMITS– Various statutory (default) speed limits,
including:• On rural roads day:• In city streets:• In alleys:• Etc.
Altering the “Default” Limit
• Should US 75’s speed limit be 30 MPH inside city limits?
• Jurisdictions can change default speed limits with restrictions
Texas Transportation Commission
• 3 member commission that oversees TxDOT
• Political appointees• Given power to change speed limit of:
– Any non-city road in state highway system– Any limited-access road in state highway
system, even if in city• TTC speed limits overrule any other limits
Powers of TTC• § 545.353. AUTHORITY OF TEXAS
TRANSPORTATION COMMISSION TO ALTER SPEED LIMITS.
• § 545.3531. AUTHORITY OF TEXAS TRANSPORTATION COMMISSION TO ESTABLISH SPEED LIMITS ON TRANS-TEXAS CORRIDOR.
• § 545.3535. AUTHORITY OF TEXAS TRANSPORTATION COMMISSION TO ALTER SPEED LIMITS ON CERTAIN ROADS.
• If default limit is “unreasonable or unsafe,” may declare new limit.
• Must do traffic investigation.• Must follow “Procedures for Establishing Speed Zones.”
TTC, Cont.
• Generally capped at• allowed in certain rural counties• allowed on “Trans-Texas Corridor”• No more environmental speed limits.• May set “wet weather” speed limit.
TTC, Cont.
• FM roads:– Allowed to consider “local public opinion” on
FM road speed limits on request of county commissioners
– But still must use “sound and generally accepted” engineering practices
Regional Tollway Authorities
• § 545.354. AUTHORITY OF REGIONAL TOLLWAY AUTHORITIES TO ALTER SPEED LIMITS ON TURNPIKE PROJECTS.
• Generally same powers as TTC on roads they own.
Regional Mobility Authorities
• § 370.033. GENERAL POWERS.• Generally same powers as TTC on roads
they own.
County Commissioners
• § 545.355. AUTHORITY OF COUNTY COMMISSIONERS COURT TO ALTER SPEED LIMITS.
• Generally same authority as TTC on county roads except:– No lower than except for residential, non-
thoroughfare roads, which can be .– Maximum speed limit is , except Harris
County can set on roads it owns. (Harris County owns some toll roads.)
Cities
• § 545.356. AUTHORITY OF MUNICIPALITY TO ALTER SPEED LIMITS.
• Generally same powers as TTC except can only set up to .
Military Reservation
• § 545.358. AUTHORITY OF COMMANDING OFFICER OF UNITED STATES MILITARY RESERVATION TO ALTER SPEED LIMITS.
• Generally same powers as TTC except can only set up to .
Minimum Speed Limit
• § 545.363. MINIMUM SPEED REGULATIONS.
• Toothless: can ignore minimum speed limit for “safe operation or [to be] in compliance with law.”
Private Roads
• § 542.006. SPEED RESTRICTIONS ON PRIVATE ROADS.
• Private, rural subdivisions can petition for speed limits.
Speed Limits and Civil Cases
• § 542.206. EFFECT OF SPEED LIMITS IN A CIVIL ACTION.
• Guilt is not proven just because you are speeding.
• Driver negligence must be proven.
Passing an Emergency Vehcile
• § 545.157. PASSING AUTHORIZED EMERGENCY VEHICLE.
• 20 under or move over.
Other• Vehicles transporting “electric power
transmission poles” may not exceed .• Vehicles transporting mobile homes may not
exceed .• Certain vehicles authorized by ports bordering
Mexico cannot exceed .• School busses may not exceed (or if not
inspected).• Speed limit is if in county park in county
bordering Gulf of Mexico.
Texas Administrative Code
• “Rules” and “regulations” created by Texas agencies.
• “Procedures for Establishing Speed Zones” in this.
Procedures for Establishing Speed Zones
• Detailed document that defines:– Regulatory and Advisory Speeds– Defense of current speed zoning practice– Actual speed zoning procedure– Procedure for approval of speed zones– Procedure for applying advisory speeds
Actual ProcedureStart
This flowchart only includes the steps involved in
determining the speed limit in a standard speed zone. As
such, it does not contain details about determining zone boundaries, school
zone speed limits, transition zones, and so forth.
Determine 85th percentile speed
Consider other factor?
Above averagecrash rate
Too few vehiclesin study
“Additional roadwayfactors”
Recommended speed limit up to 7 MPH below 85th
percentile speed.
Set recommended speed limit with
“trial runs.”
Recommended speed limit up to 10
MPH below 85th percentile speed.
“Additional roadwayfactors” and aboveaverage crash rate Recommended
speed limit up to 12 MPH below 85th
percentile speed.
Recommended speed limit within 5
MPH of 85th percentile speed.
No otherfactors
85th percentile speed is average of adjacent speed
zones.
Adjacent speedzones are less than
7 MPH different
Actual recommended speed limit established per
“professional judgment of supervising engineer.”
The actual speed limit can be up to 5 MPH above or 5-
12 MPH below the 85th percentile speed depending
on which “other factor” applies.
Environmental Speed Limit
Neverapplied
Further reduce speed limit by 5
MPH
Applied on or beforeSept. 1, 2003
Jurisdiction
City or militaryreservation
Recommended speed limit
Reduce to 60 MPH.
Above 60 MPH
Location of speed zone
TexasTransportationCommission
Recommended speed limit
Recommended speed limit
County with less than10 people per square mile
County with 10 or morepeople per square mile
Reduce to 75 MPH.
Above 75 MPH
Reduce to 70 MPH.
Above 70 MPH
Finish
Due to a 2003 law, no new ESLs may be declared, and existing ESLs may not be
further reduced. Even though the TxDOT ESL regulations
allow for up to 15 MPH below, only 5 MPH below
limits existed when this law went into effect.
60 MPHor less
75 MPHor less
70 MPHor less
Turnpike Authority
Recommended speed limit
On Texas Transportation
Corridor, regardless of
county
Reduce to 85 MPH.
Above 85 MPH
85 MPHor less
County size
Road Type
Recommended speed limit
Increase to 20 MPH.
Below 20 MPH
20 MPHor more
Recommended speed limit
Increase to 30 MPH.
Below 30 MPH
30 MPHor more
In a residence district,not major thoroughfare
Other
Road TypeMore than 2.8 million residents
2.8 million or fewer residents
Limited access
County
Other
Reality
Start
Measure 85th percentile speed
Find any excuse in the book to lower
85th percentile speed as much as
possible
Celebrate when we find a loophole or
exception that allows us to further
lower 85th percentile speed
Ignore engineering recommendations and lower speed even further by
resolution
Post super low speed limit,
thereby creating artificially high percentage of
“speeders”
“Clamp down” on “speeding crisis” and coerce even
lower limits
Questions?