Three states evaluated intersection collision warning systems to reduce the frequency of crashes by alerting drivers to conflicting vehicles.
Statewide, North Carolina, United States
Statewide, Missouri, United States
Statewide, Minnesota, United States
FHWA organized a pooled fund study of 40 States to evaluate low-cost safety strategies as part of its strategic highway safety effort. One of the strategies selected for evaluation in three states was intersection conflict warning systems (ICWSs), which are intended to reduce the frequency of crashes by alerting drivers to conflicting vehicles on adjacent approaches at unsignalized intersections.
System Costs
The following table presents itemized cost data for post-mounted signs for two-lane at two lane intersections and four-lane at two-lane intersections from the Minnesota Department of Transportation. The intersection warning systems included static signs on the major road, blank-out signs on the minor road, micro-loops on the major road, loops or micro-loops on the minor road, controller cabinets, and onsite contractor warranty, which included a 72-h response to address any system malfunction.
Countermeasure
|
Mobilization
|
Engineering
|
Construction
|
Design Build Oversight
|
Total
|
---|---|---|---|---|---|
Post-mounted on all approaches for two-lane major approach |
~$5,000
|
$11,807
|
$75,650
|
$17,000
|
$109,457
|
Post-mounted on all approaches for four-lane major approach |
~$5,000
|
$13,130
|
$103,833
|
$17,000
|
$138,963
|
The Missouri Department of Transportation provided the following approximate cost and lifespan for a post-mounted ICWS on the major approaches. Annual maintenance costs for mainline warning systems with loops on the minor routes were estimated to be $800 per year. For intersections with mainline detection using probes or microwave and wireless communication, estimated annual maintenance was $3,000 per intersection. Utility costs were an estimated $275 for mainline flashers and $400 for side street flashers annually.
Intersection Type
|
Installation Type
|
Cost
|
Lifespan
|
---|---|---|---|
Two-lane at two-lane intersection | Post-mounted ICWS on major approach |
$25,000 to $33,000
|
10-year minimum |
Four-lane at two-lane intersection | Post-mounted ICWS on minor approaches |
~$75,000
|
10-year minimum |
The North Carolina Department of Transportation ICWS cost estimates were provided for each of the installations from 1996 to 2011. The cost estimates were normalized by consumer price index to develop an average cost based on 2014. North Carolina assumed an annual maintenance cost of $500 per year, an operations cost of $125 per year, and a lifespan of 10 years for all installations.
Installation Cost
|
|||
---|---|---|---|
Condition
|
Minimum
|
Mean
|
Maximum
|
Overhead on minor only |
$20,000
|
$29,500
|
$46,000
|
Overhead on major and minor |
$20,000
|
$49,000
|
$78,000
|
Overhead on major only |
$13,500
|
$28,000
|
$49,000
|
Post-mounted only two lane |
$9,000
|
$21,600
|
$49,000
|
Post-mounted only four lane |
$49,000
|
$117,000
|
$142,500
|
Safety Evaluation of Intersection Conflict Warning Systems
Intersection Collision Warning Systems range from $9,000 to $142,500.