GROUP EXERCISE “IV”- Urban Divided
Prediction of Crash Frequency for IL 64 design as a Divided 6-Lane Street (4D)
IL 64, DuPage County, Illinois:
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
Driveways – all right-in/right-out
Residential driveways7
Minor commercial driveways (less than 50 parking spaces)7
Major commercial driveways (more than 50 parking spaces) 11
Total # of Driveways25
Proposed Design Cross-Section for Evaluation:
6 12-foot wide lanes with 42 foot wide curbed and landscaped median dividing the opposing directions of travel - Use 4D coefficients
12 foot wide paved shoulders
12 foot wide left turn lanes at all major intersections + 2 side street intersections
Total Lanes on IL-64 is 5 lanes each direction
Total number of Unsignalized Intersections with left turn lanes 2
Evergreen AvPearl Ave
Total number of Unsignalized Intersections with no median opening nor turn lanes 7
Mildred AvDiane Av
Virginia Av
Bernice AvAmy Av
Western AveNewton Ave
Highway illumination on both sides at 200 foot spacing of 400watt HPS on 40 foot mounting height on breakaway poles; Utility poles relocated out of clear zone to right-of-way line
Parking is prohibited
Unsignalized Intersections:
Mildred 700 AADT
Virginia 700 AADT
Bernice 700 AADT
Western 700 AADT
Pearl 1,500 AADT
Diane 700 AADT
Evergreen 700 AADT
Amy 700 AADT
Newton 700 AADT
Signalized Intersections:
Bloomingdale Road16,100 AADT
Shopping Center (north and south) 2,400 AADT
Main Street-Glen Ellyn16,700 AADT
Substantive Safety Performance: 3-years crash data 1986, 1987, 1988
Total Injury
CrashesCrashesDay Night
Rdwy Segment 84 26 57 27
Intersections:Total Injury DayNight
CrashesCrashes
Mildred 9 2 6 3
Virginia 12 3 9 3
Bernice 16 3 11 5
Western 11 4 7 4
Pearl 22 6 16 6
Diane 16 5 11 5
Evergreen 11 4 7 4
Amy 7 4 4 3
Newton 12 5 8 4
Bloomingdale Rd 170 68 122 48
Shopping Center 18 5 13 5
Main St-Glen Ellyn 146 45 100 46
Sub Total: 450 154 314 136
Total Segment +
Intersections: 534 180371 163
Predict the Crash Peformance for the following:
1. Proposed Cross-Section for Segment as Suburban Multilane 4D:
- Urban Multilane Base Model Multiple Vehicle Non-Driveway: (See Table 12-3 coefficients)
Nbrmv =e(a + b Ln AADT + Ln L)
= e( + * ln + ln
= e( + + )
= e( )
= crashes per year
- Proposed Cross-Section Urban Multilane Base Model Single Vehicle Non-Driveway: (See Table 12-5)
Nbrsv =e(a + b Ln AADT + Ln L)
= e( + * ln + ln
= e( + + )
= e( )
= crashes per year
- Driveway Related Crashes (see Table 12-7 coefficients)
Nbrdwu = SUM (nj Nj (AADT/15,000)t )
= x 0.033 (37,000/15,000)1.106
+ x 0.011 (37,000/15,000)1.106
+ x 0.036 (37,000/15,000)1.106
+ x 0.005 (37,000/15,000)1.106
+ x 0.018 (37,000/15,000)1.106
+ x 0.003 (37,000/15,000)1.106
+ x 0.005 (37,000/15,000)1.106
= crashes per year
Nspf rs = N Mulitiple Vehicle (non-driveway) + N Single Vehicle (non-driveway) + Nbrdwy
= + +
= crashes per year
- CMF’s for Parking (CMF1r), Roadside Objects (CMF2r), Traversable Median (CMF3r ), Lighting (CMF4r), and Automated Speed Enforcement (CMF5r ) (Table 12-19)
CMF1r = 1 + Ppk* (fpk -1.0)
Where parking is prohibited, Ppk is zero
= 1 + * (fpk -1.0)
= 1.00
CMF2r = foffset x Dfo x pfo + (1 – pfo)
For street lighting poles at 200 foot spacing on 2 sides located 18 feet from travel lane, foffset = 0.0614 (extrapolated), pfo = 0.036 (Tables 12-20 and 12-21)
= x 2 x (5280/ ) x + (1 – )
=
CMF3r for the 42 foot transversable median without
barrier from Table 12-22 =
Lighting (Table 12-23)
CMF4r = 1- (pnr x (1.0 – 0.72 pinr – 0.83 ppnr ))
For 4D: pnr= 0.410, pinr=0.364, ppnr=0.636
=
CMF5r for automated speed enforcement
Is 1.00 as there is no automated speed
enforcement for this section of IL 64
- Predicted Crash Frequency with CMF’s Applied
Nbr = Nspf rs x CMF1r x CMF2r x CMF3r
= x x x
x x
= crashes per year
- Pedestrian Crashes (Table 12-17, Posted SL>30 mph)
Npedr = Nbr x fpedr for 4D, fpedr = 0.019
= x
= crashes per year
- Bicycle Crashes (Table 12- 18, Posted SL>30 mph)
Nbiker = Nbr x fbiker for 4U, fbiker = 0.005
= x
= crashes per year
- Proposed Base Roadway Predicted Crashes for Segment (multilane Suburban 4D)
Ntotal = Nbr + Npedr + Nbiker
= + +
= crashes per year
Is the Predicted Crash Frequency Performance for the proposed Divided Multilane Cross-Section less than Substantive Safety Performance value?
Predicted Segment Crashes per year =
Substantive Safety Performance =
=
Is Substantive Safety Performance safer than the Predicted Crash Frequency?
2. Proposed Signalized Intersection of Bloomingdale Road at IL 64 with:
- Dual-Left Turn lanes on IL 64 – Single Left Turn lanes on Bloomingdale Road
- “Protected Left Turn” phasing on all 4 approaches
- Right Turn lanes on all 4 approaches
- Overhead Signals with Signal Head per Lane + 2 Signal Indications for each left turn movement
- Lighting
- Pedestrian Volume = 150 per day
- Maximum number of crossing lanes = 10
- Two Bus Stops, No Schools, One Alcohol Establishment
- Urban Multilane (multiple vehicle crashes w/o ped&bike) (Table 12-19)
Nbimv =exp(a + b ln(AADTMajor) + c ln(AADTMinor)
=exp(-10.99 + 1.07ln(37,000) + 0.23ln(16,100)
= exp( + + )
= exp( )
= crashes per year
- Urban Multilane (single vehicle crashes w/o ped & bike) Table 12-25
Nbisv =exp(a + b ln(AADTMajor) + c ln(AADTMinor)
=exp(-10.21 + 0.68ln(37,000) + 0.27ln(16,100)
= exp( + + )
= exp( )
= crashes per year
Nspf int = Nbimv + N bisv
= +
= crashes per year
- Intersection Related CMF’s
CMF1i (lttnln) = 0.66 for left turn lanes on all four approaches
CMF2i (prot turn) = 0.944 = 0.78 protected left-turn lanes on four approaches
CMF3i (rttnln) = 0.85 for right turn lanes on major road approaches
CMF4i (Prob rttrn) = none = 1.00
Lighting
CMF5i = 1- 0.38 Pnr
For 4SG intersection type, Table 12-44,
pnr = 0.235
= 1- 0.38 x
=
CMF6i (Prob rttrn) = none = 1.00
- Base Predicted Crashes for Bloomingdale and IL 64
Nbi = Nspf int x CMF1i x CMF2i x CMF3i
x CMF4i x CMF5i x CMF6i
= x x x
x x x
= crashes per year
- Urban Multilane Ped and Bike Collisions
1). Number of vehicle-ped collisions per year for base conditions at a signalized intersection
Npedbase = exp(a + b ln(AADTtot) + c ln(AADTmin/AADTmaj) + d ln(PedVol) + e(nlanesx) (Table 12-14)
= exp(-9.53 + 0.40ln(53,100) + 0.26ln(16,100/37,000) + 0.45ln(150) + 0.04(10))
= exp( + + +
+
= exp( )
= crashes per year
2) Npedi = Npedbase (CMF1p x CMF2p x CMF3p)
CMF1p for Bus Stops (Table 12-28):CMF1p = 2.78
CMF2p for School presence (None, Table 12-29): CMF2p= 1.00
CMF3p for Alcohol Sales presence (Table 12-30): CMF3p= 1.12
= 0.065( x x )
= crashes per year
3) Nbikei = Nbi x fbikei (Table 12-17)
Nbi = 12.74, fbikei = 0.015
Nbikei = x
= crashes per year
- Urban Multilane Total Predicted Crash Frequency
Npredicted int = Nbi + Npedi + Nbikei
= + +
= crashes per year
Is the Predicted Crash Frequency Performance for the proposed design for the Intersection of IL 64 with Bloomingdale Road less than the Substantive Safety Performance value?
Predicted Intersection Crash Frequency =
Substantive Safety Performance =
=
Is Substantive Safety Performance safer than the Predicted Crash Frequency?
1
Exercise IV – Prediction of Crashes for IL 64-North Avenue proposed Design as a Suburban Multilane Highway