Countermeasures That Countermeasures That WorkWork
Transportation Safety Transportation Safety ConferenceConference
Pierre, SDPierre, SD
February 22, 2007February 22, 2007
Data Driven SafetyData Driven Safety
67% of crashes in SD are the 67% of crashes in SD are the result of roadway departures!result of roadway departures!
Fatalities are generally the Fatalities are generally the result of rollovers or striking result of rollovers or striking fixed objects after running off fixed objects after running off the road.the road.
So HowSo How Do We Keep More of Do We Keep More of These Vehicles on the Road??These Vehicles on the Road??
First Offensive Tool: First Offensive Tool: Signs, Delineation & Pavement Signs, Delineation & Pavement
MarkingMarking Good case study for this: Mendocino Good case study for this: Mendocino
County, CACounty, CA They demonstrated just how effective They demonstrated just how effective
signs are as a low-cost safety signs are as a low-cost safety measure.measure.
Mendocino reduced its crashes by a Mendocino reduced its crashes by a startling 42.1 percent from 1992 to startling 42.1 percent from 1992 to 1998 at a cost of $79,260 over the 6-1998 at a cost of $79,260 over the 6-year period. year period.
"We believe that the most cost-"We believe that the most cost-effective method for enhancing effective method for enhancing safety on rural roads is to make safety on rural roads is to make the driver more aware of road the driver more aware of road conditions through consistent conditions through consistent signing and markings“. signing and markings“.
Eugene C. Calvert, P.E., former director of Eugene C. Calvert, P.E., former director of transportation with MCDOT transportation with MCDOT
Does the Mendocino Co study have Does the Mendocino Co study have
relevant information for us??relevant information for us??
MCDOT is responsible for maintaining MCDOT is responsible for maintaining
and improving 1,018 miles of and improving 1,018 miles of
secondary roads - both paved and secondary roads - both paved and
unpaved local roads.unpaved local roads.
ADT ranges from approx. 18,000 cars ADT ranges from approx. 18,000 cars
per day to as few as 20 cars per day.per day to as few as 20 cars per day.
Mendocino County focused on improving Mendocino County focused on improving
signage because installing signs is signage because installing signs is
cheaper than improving the road cheaper than improving the road
geometry by widening or flattening geometry by widening or flattening
curves.curves. Installation of each sign costs Installation of each sign costs
Mendocino County about $107 for Mendocino County about $107 for labor and materials. Quite a few labor and materials. Quite a few signs can be installed for an amount signs can be installed for an amount that would pay for very little in that would pay for very little in construction realignment.construction realignment. (1998 Data)(1998 Data)
“End Road Work”???
Broadening the perspectiveBroadening the perspective
Pavement marking
signs
Clear Zone
Guard rail
Delineation of objects in the clear zone
The “Killer” mailbox
A hazard for a run-off-the-road A hazard for a run-off-the-road incidentincident
The Pavement Edge The Pavement Edge DropoffDropoff
It doesn’t have to be this way!
Correcting Surface DefectsCorrecting Surface Defects
Good corrective measure by Good corrective measure by SDDOT maintenance personnelSDDOT maintenance personnel
The real tough situations:The real tough situations:
Requires long-term planning, Requires long-term planning, acquiring project level funding acquiring project level funding
and prioritization and prioritization
1:8 to 1 inslope and virtually no shoulder.
Approx. 2,500 ADT.
A brief look at unpaved A brief look at unpaved roads with geometric roads with geometric
defectsdefects
Crown?
Some have too little crown, this one has too much.
Imagine a pot trailer on this road.
High Shoulder – Obstruction of High Shoulder – Obstruction of DrainageDrainage
There are too many of these situations
A very good example.
What’s wrong with this picture??
The right way!
Substandard Surface Aggregate
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