Today Misc slides from Evans Crash risk and age Road crash factors Vehicle crash factors Environmental crash factors

Misc Slides from Evans

Source: Evans, Leonard. Traffic Safety. Bloomfield Hills, MI; Science Serving Society; 2004

Source: Evans, Leonard. Traffic Safety. Bloomfield Hills, MI; Science Serving Society; 2004 used by permission for CE 552 in class use only

Crash risk and age Older Drivers

NCHRP 500 series Volume 9: Older Driver Identifies/characterizes the problem (what we are now discussing) Recommends remedial action/countermeasure s (later in the semester)

Why?

See interesting illusion applet

Age and vision 20 Year old vision 60 year old vision

Grandpa hopes this is serious exaggeration 75 year old vision estimate

BMW, Hummer night vision systems because it's unaffected by ambient light, Night Driver enables drivers to see beyond oncoming headlight glare… …up to five times further than with headlights alone

Older Population Traffic Safety Fact Sheet (DOT-HS ) Older Population Traffic Safety Fact Sheet (DOT-HS ) also includes state by state comparison data

Why does this look different?

Age and vision the olny iprmoetnt tihng is that the frist and lsat ltteer be at the rghit pclae!

Crash risk and age Young Drivers

NCHRP 500 series Volume 19: Young Drivers Drivers Identifies/characterizes the problem (what we are now discussing) Recommends remedial action/countermeasure s (later in the semester)

See also these references if you are interested: Generational perspective on teen and older drivers on traffic safety in rural and urban communities Generational perspective on teen and older drivers on traffic safety in rural and urban communities Younger older interaction LIDAR study sight distance LIDAR study Visual acuity paper Visual acuity

Road crash factors The highest design/most :forgiving road” – High speed design (curvature) – Full access control – Forgiving roadsides (slopes, obstacles) – Grade separated intersections – Median separation 4 to 20 times or more safer than other roads

Access control Eliminates conflict points Does not require full access control Some roads must have access at many points – But still may be reduced

Medians Wide (grass) “Narrow” with barrier Narrow (painted or grass) 30 foot median can reduce encroachment by percent 6:1 desirable to prevent rollover, but will not slow errant vehicles as much (I-35 case, 4:1 to 6:1 to cable)

Cross section Lane width: feet is best Shoulder width up to 10 feet (not independent of lane width) and surface type/condition (edge drop) Cross slope (drainage, esp on superelevated curves) Sight distance, esp. on curves Curves (esp. at night, poor weather) Grades Combinations of factors/expectancy Bridges/structures Passing zones

Vehicle Factors

Video “c” ABS ESC

Source: Evans, Leonard. Traffic Safety. Bloomfield Hills, MI; Science Serving Society; 2004 used by permission for CE 552 in class use only

Environmental Factors

Source: Evans, Leonard. Traffic Safety. Bloomfield Hills, MI; Science Serving Society; 2004 used by permission for CE 552 in class use only