GROUP EXERCISE “II” – Urban Multilane
IL 64, DuPage County, Illinois:
IL Route 64, an east-west state highway initiates at Lake Michigan in the City of Chicago and
terminates at the Mississippi River at the west border of Illinois. In DuPage County, 1987
population of 780,000, IL Route 64 is known as North Avenue traversing the cities of Elmhurst
and Villa Park and through rural unincorporated areas west to St.Charles Illinois in Kane
County. IL Route 64 was improved to 4 lanes in the 1960’s throughout this length with
intersection improvements at major crossroads such as other state routes and county routes
consisting of left turn lanes and traffic signal control during the 1960’s and 1970’s. Posted
Speed Limit = 45 mph
Cross-Section:
4 12-foot wide lanes with double yellow centerline dividing the opposing directions of
travel
8 foot wide aggregate shoulders
12 foot wide left turn lanes at all major intersections
No left turn lanes at minor street intersections nor at commercial driveways
No highway illumination other than some minor intersection lighting by local municipalities
and the County Highway Department; no automated speed enforcement
Study Section: Bloomingdale Road to Main Street-Glen Ellyn
Length of Section = 0.97 miles
AADT
= 37,000 vpd
No Horizontal Curves; 2.8% vertical curve west of Shopping Center for 0.35 mi
Side slope = 1:6
Trees and Power poles 18.0 feet from edge of pavement; Hazard Rating of 5.0
Driveways:
Residential driveways (minor)
Minor commercial driveways (less than 50 parking spaces)
Major commercial driveways (more than 50 parking spaces)
Total # of Driveways
7
7
10
24
Total number of Unsignalized Intersections with left turn lanes
0
Total number of Unsignalized Intersections without turn lanes
Mildred Av
Diane Av
Virginia Av
Evergreen Av
Bernice Av
Amy Av
Western Ave
Newton Ave
Pearl Ave
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Exercise II – Prediction of Crashes for IL 64-North Avenue as a Suburban Multilane Highway
1
Unsignalized Intersections:
Mildred
Virginia
Bernice
Western
Pearl
Diane
Evergreen
Amy
Newton
700 AADT
700 AADT
700 AADT
700 AADT
1,500 AADT
700 AADT
700 AADT
700 AADT
700 AADT
Signalized Intersections:
Bloomingdale Road
Shopping Center (north and south)
Main Street-Glen Ellyn
16,100 AADT
2,400 AADT
16,700 AADT
Substantive Safety Performance: 3-years crash data 1986, 1987, 1988
Total
Crashes
84
Injury
Crashes
26
Total
Crashes
Mildred
9
Virginia
12
Bernice
16
Western
11
Pearl
22
Diane
16
Evergreen
11
Amy
7
Newton
12
Bloomingdale Rd
170
Shopping Center
18
Main St-Glen Ellyn 146
Sub Total:
450
Total Segment +
Intersections: 534
Rdwy Segment
Intersections:
Day
57
Night
27
Injury
Crashes
2
3
3
4
6
5
4
4
5
68
5
45
154
Day
Night
6
9
11
7
16
11
7
4
8
122
13
100
314
3
3
5
4
6
5
4
3
4
48
5
46
136
180
371
163
Exercise II – Prediction of Crashes for IL 64-North Avenue as a Suburban Multilane Highway
2
1. Predict the Crash Frequency Performance for the following:
a. Suburban Multilane Base Model Multiple Vehicle Non-Driveway:
e(a + b Ln ADT + Ln L)
Nspf mv =
= e(
=
e(
= e(
=
+
* ln
+
+
+ ln
)
)
crashes per year
b. Suburban Multilane Base Model Single Vehicle Non-Driveway:
e(a + b Ln ADT + Ln L)
Nspf sv =
= e(
+
* ln
e(
+
+
= e(
)
=
=
+ ln
)
crashes per year
Exercise II – Prediction of Crashes for IL 64-North Avenue as a Suburban Multilane Highway
3
c. Driveway Related Crashes:
Nspf dwy = SUM (nj Nj (ADT/15,000)t )
x 0.182 (37,000/15,000)1.172
=
+
x 0.058 (37,000/15,000)1.172
+
x 0.198 (37,000/15,000)1.172
+
x 0.026 (37,000/15,000)1.172
+
x 0.096 (37,000/15,000)1.172
+
x 0.018 (37,000/15,000)1.172
+
x 0.029 (37,000/15,000)1.172
=
crashes per year
Nspf rs = Nspf mv(non-driveway) + Nspf sv(non-driveway) + Nspf dwy
=
+
+
=
d. CMF’s for Parking, Roadside Objects, Median Width, Lighting, and
Automatd Speed Enforcement:
CMF1r = 1 + Ppk* (fpk -1.0)
Where parking is prohibited, Ppk is zero
=1+
* (fpk -1.0)
=
Exercise II – Prediction of Crashes for IL 64-North Avenue as a Suburban Multilane Highway
4
CMF2r = foffset x Dfo x pfo + (1 – pfo)
For power poles at 160 foot spacing one side located 18 feet
from travel lane, foffset = 0.0614
pfo = 0.037
=
x (5280/
+ (1 –
)x
)
=
CMF3r =
Does not apply, it’s only applicable to divided roadway
segments. This segment is undivided with double yellow centerline
CMF4r = 1- (pnr x (1.0– 0.72 pinr – 0.83 ppnr ) )
Base condition is no lighting, hence, CMF4r = 1.000
=
CMF5r =
for Automated Speed Enforcement
Base condition is no automated speed enforcement,
hence, CMF5r = 1.000
=
e. Predicted Crashes with CMF’s Applied
Nbr = Nspf rs x CMF1r x CMF2r x CMF3r x CMF4r x CMF5r
=
x
x
x
x
=
crashes per year
Exercise II – Prediction of Crashes for IL 64-North Avenue as a Suburban Multilane Highway
5
f. Pedestrian Crashes (Posted SL>30 mph)
Npedr = Nbr x fpedr
for 4U, fpedr = 0.009
=
x
=
crashes per year
g. Bicycle Crashes (Posted SL>30 mph)
Nbiker = Nbr x fbiker
for 4U, fbiker = 0.002
=
x
=
crashes per year
h. Base Roadway Crashes for Segment (multilane Suburban 4U)
Nbr = Nbr + Npedr + Nbiker
=
+
+
=
crashes per year
Exercise II – Prediction of Crashes for IL 64-North Avenue as a Suburban Multilane Highway
6
Is the Substantive Safety Performance for the geometrics for IL 64
(Driveway, Parking, and Lighting) safer than predicted value?
Substantive Safety Performance =
_____ crashes in 3 years
=
______ crashes per year
Predicted Crash Frequency with CMF’s
applied for the Segment Crashes per year =
Substantive Safety less than
Predicted Crash Frequency ?
Exercise II – Prediction of Crashes for IL 64-North Avenue as a Suburban Multilane Highway
7