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