Post on 08-May-2018
Lane Departure Safety Plan Overview
Types of crashes considered as Lane Departure:
•Centerline cross-over
• Failed to keep proper lane (e.g. Sideswipe)
•Run off the road (ROTR)
•Wrong-Way/Wrong-Side
Lane Departure Safety Plan Overview• Florida is an FHWA
Focus State for Lane Departure
• FHWA assisted with the development of the Lane Departure Safety Plan
• Lane Departure is an Emphasis Areas of the Florida Strategic Highway Safety Plan
Lane Departure Safety Plan Overview• I lost my brother-in-law in December 2016 to a lane departure
crash. He was struck by a vehicle leaving the roadway at night.
Lane Departure Safety Plan Overview• Low volume, straight, county road.
• Thermoplastic not used, paint no longer visible, RPMs no longer work properly…No maintenance.
• No visibility at night when vehicle headlights approach.
Lane Departure Safety Plan Overview
In Florida, from 2011-2013:
• 49% of all highway fatalities were the result of a lane departure crash
• A total of 3,513 fatalities from lane departure crashes over this 3-year period
Lane Departure Safety Plan Overview
Not only a State Road issue:
• Over 42% of the lane departure fatalities occur on Non-FDOT facilities
• FDOT must be proactive in working with the local agencies
Lane Departure Safety Plan Overview
Goal:• Save 140 lives per year over the next 10-year period• Request funding over the next 5-years• Implement tracking mechanisms to measure success• Engineering, Education and Enforcement (EEE)
• Education and Enforcement:• Targeted, frequent and high-visibility initiatives
• Speeding, Alcohol, Distracted and Unbelted Drivers
• Engineering: • Targeted, systemic deployment of cost-effective countermeasures
• Focus on higher fatality locations throughout the State• Opportunities in other programmed projects• District Safety Engineers will work with local agencies
Lane Departure Countermeasures
• Countermeasures to keep drivers in their lane:• Pavement Markings
• Retroreflective Pavement Markings• Raised Retroreflective Pavement Markers
• Audible and Vibratory Warnings• Rumble Striping• Profiled Thermoplastic
• Enhancements for Curves: • Signing and Marking for Curve Delineation• Internally Illuminated RPMs• High Friction Surface Treatments for Curves
• Signing and Warning for Wrong-Way Driving
Lane Departure Countermeasures
• Countermeasures to reduce severity of crash once drivers depart the lane:• Select Tree (or other hazard) Removal within Clear Zone
• Trees• Non-critical signs• Railings
• Wide Paved Shoulders• 5’ paved shoulders
• Safety Edge• Traffic Barrier Upgrades/Median Barriers
• Cable Barrier• Guardrail• Concrete Barrier
Pavement Markings
• Longitudinal Pavement Markings are the most basic form of lane departure countermeasure
• The retroreflectivity of these markings are critical to their effectiveness
• Raised Retroreflective Pavement Markers (RPMs) supplement the longitudinal lines and improve wet/night visibility
• Maintenance of pavement markings and RPMs is just as critical
Rumble Striping
• Rumble Strips are the most effective countermeasure for lane departures
• July 2015, Implemented Rumble Striping• Aggressive design
• No criteria for context consideration
• Received numerous complaints of noise pollution
Rumble Striping
• Released Roadway Design Bulletin 16-07 (08-19-16)• Removed existing Index 519 (Rumble Striping)• Used Index D519 to further develop Rumble Striping
• Reduce Noise Pollution• Accommodations for Bicyclist
• Required all projects in Design Phase to come to Central Office for review of context• Changes to Contract Plans if required• Use of new Index D519
• Released DCE Memorandum 11-16 (08-23-16)• All projects let prior to March 1, 2017 to come back to Central Office for
review of context• Changes to As-built plans if required• Use of new Index D519
Rumble Striping
NCHRP Synthesis 490:
Noise Pollution significantly reduced when located outside of a 650 ft radius from a residence
Rumble Striping
• District 2, Rumble Striping Pattern Test Project:• 5 different patterns were tested, including two Sinusoidal Rumble Striping
patterns• Various depths of cylindrical pattern• Two versions of sinusoidal patterns
• 1000-ft runs of each pattern• Noise Study conducted• Evaluated relative decibel levels
• Recently Installed (Go ride them for yourselves)!!
• Study recently finalized
• Drafting new Criteria soon
Rumble Striping
Rumble Striping Pattern Test Project Location: District 2; Suwannee County, US 90Exit 275 (Live Oak/Lee)
Rumble StripingRumble Striping Pattern Test Project Layout:Go drive it for yourself, have passenger use this layout to know what you are experiencing
Rumble Striping
10.9
6.67.3
4.6
00.7
1.2
11.82
6.22
10.62
6.22
1.02 0.82
2.72
0
2
4
6
8
10
12
14
Cylindrical, 8" Width and1/2" Depth
Cylindrical, 8" Width and3/16" Depth
Cylindrical, 8" Width and5/16" Depth
Cylindrical, 6" Width and5/16" Depth
Sinusoidal, 8" Width and1/2" Depth
Sinusoidal, 8" Width and5/16" Depth
Profiled Thermoplastic, 6"Width
Ch
ang
e in
No
ise
(d
BA
)
Rumble Strip TypeChange in Noise (dBA) SMO Change in Noise (dBA) Consultant
Noise Evaluation Results
Rumble Striping
• Rumble Striping Policy Revisions• An imminent project in D2 will be installing 5/16” sinusoidal rumble strips
and 3/16” conventional rumble strips off the stripe.
• The developmental process is expected to be completed by the end of the year.
• The final policy will likely incorporate profiled thermoplastic, conventional rumble strips, and, potentially, sinusoidal rumble strips. Depending on roadway and roadside conditions, designers will pick the most appropriate treatment.
Rumble Striping
• Temporary Traffic Control Schemes?• Index 603, lane closure.
• Index 600 now allows for 3 mile lane closure for rumble striping projects.
• Other Solutions?• Flaggers riding in the back of a truck?
• Submitted NCHRP Problem Statement• Research on alternate TTC Schemes for slow mobile
operations.
Rumble Striping
• Developing retrofit to fill-in grindings
• Specific areas where residence experience extreme hardships due to noise pollution
• Targeting specific lines within 650ft radius
Rumble StripingMicro-Surfacing Retrofit: 02/14/2017
Grinding to roughen surface and eliminate any loose thermoplastic
Grinding/Sweeping Existing Thermoplastic
Profiled ThermoplasticProfiled Thermoplastic Markings:
• Multilane: Used where paved shoulders are less than 1’-0” (Shoulder pavement durability)
• Two-Lane Two-Way: Used where there are no shoulders (MOT Constraints)
• Used near residential areas (Less noise)
Enhancements for CurvesStudy currently being conducted for the Department:
• Data collection using Curve Advisory Reporting Service (CARS)• Ballbank indicator• GPS receiver• Tablet collects and stores data electronically
• Video Data
• Inventory of existing signs and advisory speeds
• Determine if in compliance with the 2009 MUTCD• If not, plans will be developed to improve signing, marking and possibly
surface friction
Enhancements for CurvesEnhancements will include:
• Horizontal Alignment Warning Signs• Chevrons
• Arrows
• Advisory Speed Signs
• High Friction Surface Treatments
Enhancements for Curves• High Friction Surface Treatments
• Polish resistant aggregate in polymer resin binder
• Reduces horizontal curve lane departures• Average 32% reduction of total crashes
• Average 75% reduction of wet weather crashes
• Most effective in “tight” curves
• Recommended on curves where there is a crash history
HFST
Enhancements for Curves• High Friction Surface Treatments Performance:
0
10
20
30
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60
70
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90
100
0.000 0.010 0.020 0.030 0.040 0.050 0.060 0.070 0.080 0.090 0.100
Fric
tio
n N
um
ber
Texture-MPD (in.)
DENSE
OPEN
LGD
HFST
Roadside Hazards• Does railing meet Clear
Zone requirements?
• What is the purpose?• Protect the root system of
the Pine Tree.
• P.S. Pine trees have tap roots…
• Is Pine Tree worth the cost, or reduced safety?
• What might happen whena vehicle impacts the railing?
Roadside Hazards• Results of impact with
similar Guiderail
• Horizontal members become spearing hazards
• Notice what is at the tip of the spear
• Thankfully, nobody was injured in this crash
Roadside Hazards• Although sign supports are “crashworthy”, may not be impacted as
crash tested
• This is hit was at an angle outside of the envelope of the crash testing
Safety Edge• Abrupt and deep drop-offs on edge of pavement may cause drivers to
overcorrect when reentering travel lane
• Caused by tire scrubbing the edge
Safety Edge• Safety Edge incorporates a 30 degree wedge into the edge of
pavement which reduces the potential for drivers overcorrecting
• Other benefits include:• Improves compaction on pavement edge
• Reduces Raveling, Cracking of the pavement edge
• Provides more aesthetic edge of pavement
Traffic BarriersDeflection Space vs. Impact Severity different barrier types:
• Flexible Systems – High Tension Cable Barrier• Capture and Redirect• High Deflection• Barrier Absorbs Most Energy
• Semi-Rigid Systems – W-Beam Guardrail• Contain and Redirect• Limited Deflection• Barrier and Vehicle share in the Dissipation of Energy
• Rigid Systems – Concrete Barriers & Traffic Railings• Redirects• Effectively No Deflection• Vehicle Absorbs Energy
Shape of Barrier Vehicle Roll and Climb
Questions
Gevin McDaniel, P.E.
State Standard Plans Engineer
Central Office, Roadway Design
(850) 414-4284
gevin.mcdaniel@dot.state.fl.us
Ed Cashman, P.E.
Standard Plans Engineer
Central Office, Roadway Design
(850) 414-4314
edward.cashman@dot.state.fl.us