MAY 2016

WIM Site Location

WIM #38 is located on I-535 near Duluth in St Louis county.

System Operation

WIM #38 was operational for the entire month of May 2016. Volume was computed using all monthly data.

System Calibration

WIM #38 was most recently calibrated on 2015-08-10. Table 1 summarizes the front axle weights of class 9s by lane 1. Table 1 indicates that the class 9 front axle weights were all within ±9% of baseline calibration values for all lanes. Figure 1 shows the distribution of gross vehicle weights (GVW) in the Class 9s at this site for the last 12 months of operation 2. Figure 2 depicts the average front axle weight as a percent difference from the first full month following calibration.

Summary of Volume Statistics Total Monthly Volume: 1024533 | Passenger Vehicles: 961647 | Heavy Commercial Vehicles: 62886

Monthly Average Daily Traffic (MADT): 33049 | Monthly Heavy Commercial Average Daily Traffic (MHCADT): 2029

See Table 2 for vehicle class breakdown

Passenger Vehicles (PVs) and Heavy Commercial Vehicles (HCVs)

Volume trends. NB vehicles typically reached highest volume levels on Fridays, with lowest volumes reported on Sundays. SB vehicles typically reached highest volume levels on Fridays, with lowest volumes reported on Sundays (see Figure 3 and 4).

Passenger Vehicles (PVs)

Volume trends. On an average 24-hour day (see Figure 5), NB PVs generally reached peak volume levels between 03 PM and 05 PM. Similarly, SB PVs peaked in volume between 03 PM and 05 PM

Heavy Commercial Vehicles (HCVs)

Volume trends. On an average 24-hour day, HCVs traveling NB typically reached peak volume levels between 03 PM and 05 PM, while volume going SB peaked between 03 PM and 05 PM. See Figure 6. Out of all HCVs, the two highest traffic volumes were generated by Class 9's and Class 5's.

Overweight HCVs

Volume trends. Of a total of 62886 HCVs, 2712 of them were overweight 3. These overweight HCVs contributed to 0.3% of total monthly volume, and 4.5% of total monthly HCV volume. NB overweight vehicles typically reached highest numbers on Wednesdays, with lowest volumes reported on Sundays. SB overweight vehicles tended to reach highest volumes on Wednesdays, with lowest volumes reported on Sundays. See Figure 3 . The top two overweight violators by class were the class 9 and class 10 vehicles . Overall, overweight vehicles tended to reach peak volume concentrations during typical business hours, with 65.4% of all overweight vehicles traveling SB this month (see Figure 7 & 8). Figure 9 shows the number of vehicles exceeding 88,000 pounds that crossed the WIM over the last 12 months. The highest number of 88,000+ vehicles within the last 12 months occurred in July. WIMs are currently used as a screening tool for weight enforcement, and it is estimated that the WIM scales can measure gross vehicle weights (GVW) within 90-95% of static weight scale measurements. Due to the possibility of measurement error, vehicles exceeding 10% of their legal weight limits (or 1.1 times their legal weight limits) are considered overweight in this report 4. Using normal load limits ,63 NB vehicles exceeded 88,000 pounds (35 vehicles were Class 10's; 18 vehicles were Class 13's). Of vehicles traveling SB,

66 NB vehicles exceeded 88,000 pounds (35 vehicles were Class 10's; 25 vehicles were Class 13's). Refer to Table 3 for the Top 10 highest recorded GVWs from Classes 9 and 10 from May 2016.

Loaded vs. Unloaded HCVs. Figure 10 shows the GVW distributions of Class 9s and 10s in May 2016. Data suggests that there were greater numbers of fully_loaded Class 9's than empty Class 9's traveling NB, while there were more fully_loaded Class 9's than empty traveling SB. Data also suggests that there were more empty Class 10's than fully_loaded traveling in the NB direction. In the SB direction, there were more fully_loaded class 10 vehicles.

Freight Totals. A total of 434446 tons of freight was recorded to have crossed the WIM. More freight was shipped SB (53.4%) than NB (46.6%). See Table 4 and Figure 11 for more freight information.

Infrastructure Considerations

Bridge. Bridge No. 9030 (Blatnik Bridge) is approximately 1.1 miles south of WIM #38, and Bridge No. 69808 is 0.45 miles south of WIM #38. A pair of bridges also exists 0.4 miles north of WIM #38 (Bridge No. 69801C on the NB side and Bridge No. 69801N on the SB side). WIM #38 recorded a total of 1024533 vehicles with a combined GVW of 6398618 kips (1 kip = 1,000 pounds = 0.5 tons) in May 2016. See Table 5 and Figures 12-13 for GVW information by vehicle class and lane.

Pavement Design. A total of 36006 equivalent single axle loads (ESALs) passed over the pavement at this site. Approximately 54.1% of all ESALs were recorded SB while 45.9% was observed NB. In particular, 65% of all ESALs were generated by the Class 9's (Class 9's

were also responsible for generating 22% of total GVW observed this month). See Table 6 and Figures 14-15 for more information on ESALs (Table 6 also provides flexible ESAL factors for each vehicle class using a terminal serviceability of 2.5 and a structural number of 5).

WIM monthly reports can be found at: http://www.dot.state.mn.us/traffic/data/reports-monthly-wimnew.html

MnDOT's vehicle classification scheme and vehicle class groupings for traffic forecasting can be found at: http://www.dot.state.mn.us/traffic/data/data-products.html#weight

To request this document in an alternative format, please call 651-366-4718 or 1-800-657-3774, or email your request to ADArequest.dot@state.mn.us. Please request at least one week in advance.

• 1 Front axle weights of Class 9s are monitored on a monthly basis to assure performance between calibrations. The current goal of the WIM scale calibration is to have each individual axle weight stay within a range of ±9% of baseline calibration values

• 2 Previous WIM research indicates that unloaded Class 9s typically weigh 28-32 kips, while loaded Class 9s generally fall in the 70-80 kip range. More recent data from several WIM sites suggests that the unloaded Class 9 range may have moved a little higher over time (due to increased presence of sleeper cabs, etc.), although these ranges are also thought to be site-specific.

• 3 An HCV is considered overweight during normal load limits in this report if they satisfy any of the following 1) exceed a gross vehicle weight (GVW) of 80,000 pounds, 2) exceed any of the legal weight maximums on any axle configurations (legal maximums are: single axle = 20,000 pounds; tandem axles spaced 8' or less = 34,000 pounds; tridem axles spaced 9' or less = 43,000 pounds; quad axles spaced 13' or less = 51,000 pounds). Monthly reports use this standard regardless of the time of year however, the Winter Load Increase (WLI) allows a 10% across the board increase in axle and gross vehicle weights without a permit on US, state routes, and county roads. An HCV is considered overweight during Winter Load Increase(WLI) if they satisfy any of the following 1) exceed a gross vehicle weight (GVW) of 88,000 pounds, 2) exceed any of the legal weight maximums on any axle configurations (legal maximums are: single axle = 22,000 pounds; tandem axles spaced 8' or less = 37,400 pounds; tridem axles spaced 9' or less = 47,300 pounds; quad axles spaced 13' or less = 56,100 pounds). An overweight HCV is only included once in the overweight volume calculations regardless of how many of the aforementioned conditions are violated. For information on MN weight limit dates and statutes: http://www.mrr.dot.state.mn.us/research/seasonal_load_limits/sllindex.asp

• 4 For example, Class 9s and 10s can legally have gross vehicle weights up to 80,000 lbs (with the exception of permitted loads) during normal load limits. To account for measurement error on the WIM scales, those exceeding 10% of the legal GVW

maximum (or 1.1 times the legal GVW) should be screened (e.g., 80,000 lbs + 8,000 lbs = 88,000 lbs). Similarly during WLI vehicles weighing 96,800 lbs should be screened.

Vehicle Weights (Kips)

Jun 2015

Jul 2015

Aug 2015

Sep 2015

Oct 2015

Nov 2015

Dec 2015

Jan 2016

Feb 2016

Mar 2016

Apr 2016

May 2016

88-90 1132 1686 560 91 66 32 33 29 35 14 9 25

90-92 482 846 314 74 44 26 12 32 24 7 2 17

92-94 260 383 160 51 29 13 14 24 15 7 0 16

94-96 191 213 123 45 28 20 9 10 8 7 2 10

96-98 189 124 75 25 13 6 6 10 9 3 0 8

98-100 133 79 57 23 13 6 4 12 3 5 2 4

>100 458 302 215 123 114 62 50 44 31 13 14 48

Total 2845 3633 1504 432 307 165 128 161 125 56 29 128

Table 1 Class 9 Front Axle Weight by Lane

Month Lane 1 (Kips)

Front Axle +/- 9%

Lane 2 (Kips)

Front Axle +/- 9%

Lane 3 (Kips)

Front Axle +/- 9%

Lane 4 (kips)

Front Axle +/- 9%

September 2015

11.60 0.00 10.96 0.00 11.15 0.00 11.07 0.00

October 2015 11.52 -0.73 10.72 -2.21 10.95 -1.77 10.76 -2.75

November 2015

11.32 -2.40 10.59 -3.34 10.95 -1.80 10.67 -3.59

December 2015

11.28 -2.76 10.33 -5.70 10.69 -4.06 10.51 -5.03

January 2016 11.28 -2.76 10.10 -7.78 10.51 -5.73 10.54 -4.74

February 2016 11.08 -4.53 10.14 -7.45 10.57 -5.14 10.35 -6.52

March 2016 11.12 -4.15 10.05 -8.26 10.66 -4.38 10.31 -6.87

April 2016 11.09 -4.37 10.11 -7.69 10.64 -4.54 10.46 -5.46

May 2016 11.22 -3.29 10.36 -5.42 10.90 -2.22 10.75 -2.91

Table 2 Vehicle Classification Data Vehicle Class

Monthly Average Daily Volume

Monthly Total Volume

Monthly Total Volume Percentage

Monthly Total Overweight Vehicles

Monthly Total Overweight Percentage

1 4 117 0 0 0

2 21700 672705 65.7 0 0

3 9317 288825 28.2 0 0

4 37 1161 0.1 87 3.2

5 591 18320 1.8 176 6.5

6 191 5923 0.6 280 10.3

7 27 834 0.1 290 10.7

8 103 3184 0.3 65 2.4

9 942 29202 2.9 1187 43.8

10 101 3141 0.3 552 20.4

11 19 597 0.1 8 0.3

12 1 44 0 7 0.3

13 16 481 0 60 2.2

TOTAL 33049 1024533 100 2712 100

Table 3 Top 10 Gross Vehicle Weight, Class 9 and 10 Date Day of Week Time Vehicle Class Direction Lane GVW (lbs)

2016-05-24 Tuesday 04:14:13 10 NB 1 141.75

2016-05-22 Sunday 18:43:15 10 NB 1 139.93

2016-05-19 Thursday 04:23:11 10 NB 1 135.85

2016-05-31 Tuesday 04:55:44 10 NB 1 132.79

2016-05-17 Tuesday 17:02:25 10 NB 1 130.79

2016-05-20 Friday 04:19:17 10 NB 1 126.07

2016-05-25 Wednesday 05:06:17 10 NB 1 126.07

2016-05-18 Wednesday 04:54:11 10 NB 1 125.96

2016-05-27 Friday 12:29:16 10 NB 2 121.85

2016-05-25 Wednesday 04:36:47 10 NB 1 111.79

Table 4 Freight Summary

Vehicle Class Direction

Weight of Empty Vehicle (Kips)

Total Number of Vehicles

Number of Empty Vehicles

Percentage of Empty Vehicles

Total Weight of Vehicles with Freight (Kips)

Total Weight of Empty Vehicles (Kips)

Total Weight of Freight (Tons)

4 NB 15 609 131 21.5 16697 1667 4764

5 NB 8 8528 1587 18.6 104681 11276 24576

6 NB 19 2330 504 21.6 59516 8346 12411

7 NB 11.5 339 0 0 19083 0 7592

8 NB 31 1231 763 62 19712 16255 2602

9 NB 33 13197 3773 28.6 590795 105703 139902

10 NB 33.5 670 235 35.1 28077 6973 6752

11 NB 36.5 294 103 35 9801 3059 1415

12 NB 36.5 26 6 23.1 1238 142 254

13 NB 31.5 105 0 0 7951 0 2322

TOTAL **** **** 27329 7102 **** 857552 **** 202590

Vehicle Class Direction

Weight of Empty Vehicle (Kips)

Total Number of Vehicles

Number of Empty Vehicles

Percentage of Empty Vehicles

Total Weight of Vehicles with Freight (Kips)

Total Weight of Empty Vehicles (Kips)

Total Weight of Freight (Tons)

4 SB 15 514 94 18.3 14059 1222 3879

5 SB 8 9199 1138 12.4 119828 8286 27670

6 SB 19 3401 551 16.2 88882 9786 17366

7 SB 11.5 468 0 0 27210 0 10914

8 SB 31 1850 930 50.3 33534 21808 2507

9 SB 33 15059 6323 42 541764 179995 126738

10 SB 33.5 2369 505 21.3 127265 15686 32411

11 SB 36.5 284 35 12.3 14020 1088 2466

12 SB 36.5 17 5 29.4 739 117 150

13 SB 31.5 360 0 0 26851 0 7756

TOTAL **** **** 33521 9581 **** 994151 **** 231856

GRAND TOTAL **** **** 60850 16683 448 1851703 391409 434446

Table 5 Gross Vehicle Weight by Class and Lane Vehicle Class NB Driving Lane NB Passing Lane SB Passing Lane SB Driving Lane Total Percentage

1 54 39 36 30 159 0

2 677059 503888 657520 645755 2484222 38.9

3 404639 388302 352445 510102 1655488 25.9

4 6415 11949 2872 12409 33646 0.5

5 49312 66644 29953 98161 244070 3.8

6 19100 48762 6982 91686 166530 2.6

7 2904 16179 262 26948 46293 0.7

8 10807 25161 6037 49305 91310 1.4

9 76304 620194 45945 675814 1418257 22.2

10 8114 26936 5210 137741 178001 2.8

11 337 12523 38 15070 27968 0.4

12 277 1102 140 715 2235 0

13 467 7484 0 26851 34802 0.5

TOTAL 1255790 1729164 1107440 2290587 6382981 100

GVW/LANE 19.67 27.09 17.35 35.89 100 0

Table 6 ESALs by Class and Lane and Flexible ESAL Factors

Vehicle Class NB Driving Lane

NB Passing Lane

SB Passing Lane

SB Driving Lane Total Percentage

Flexible ESAL Factor

1 0 0 0 0 0 0 0.0088

2 73 45 76 72 266 0.75 8e-04

3 125 106 109 171 510 1.43 0.0037

4 130 215 96 208 649 1.82 1.16

5 468 767 228 1247 2710 7.61 0.31

6 500 740 94 1395 2729 7.67 0.95

7 55 227 6 457 745 2.09 1.84

8 249 322 61 536 1167 3.28 0.76

9 1377 10090 612 11404 23482 65.97 1.66

10 188 264 57 1920 2429 6.82 1.6

11 2 163 0 326 491 1.38 1.69

12 5 12 2 12 32 0.09 1.39

13 4 113 0 267 385 1.08 1.64

TOTAL 3178 13063 1340 18014 35595 100 13

ESALS/LANE 8.9 36.7 3.8 50.6 100 -- --

Table 7 Site Summary: Volume and Vehicle Class

Month Total Volume

Monthly ADT

Monthly HCADT

Passenger Vehicles

Passenger Vehicles %

Heavy Commercial Vehicles

Heavy Commercial Vehicles %

Heavy Commercial Vehicles in Driving Lane %

Heavy Commercial Vehicles in Passing Lane %

Jul 2015 1355905 43739 2919 1265427 93.3 90478 6.7 60 40

Aug 2015 1315961 42450 2693 1232463 93.7 83498 6.3 61.1 38.9

Sep 2015 1239478 41547 2620 1160878 93.7 78600 6.3 60.8 39.2

Oct 2015 1259563 40631 2614 1178543 93.6 81019.7 6.4 60.6 39.4

Nov 2015 922010 30734 1852 866454 94 55555.9 6 57.7 42.3

Dec 2015 938505 30274 1720 885171 94.3 53334.4 5.7 59.1 40.9

Jan 2016 860350 27753 1596 810877 94.2 49473 5.8 60.4 39.6

Feb 2016 873265 30113 1701 823949 94.4 49316.5 5.6 59.8 40.2

Mar 2016 943741 30443 1699 891064 94.4 52676.9 5.6 58.9 41.1

Apr 2016 959416 31980 1733 907419 94.6 51997.4 5.4 58.3 41.7

May 2016 1024533 33050 2029 961647 93.9 62886.4 6.1 58.8 41.2

TOTAL 11692727 -- -- 10983892 -- 708836 -- -- --

AVERAGE 1062975 34792 2107 998536 94 64440 6 60 40

ESALs

Month

ESALS NB Passing Lane

ESALS NB Driving Lane

ESALS SB Driving Lane

ESALS SB Passing Lane

Total ESALS

Driving Lane ESALS %

Passing Lane ESALS %

Pavement Life Decrease Months

Jul 2015 8230 33551 4072 41734 87588 57 43 23.7

Aug 2015 6088 22771 3649 31584 64093 59 41 12.2

Sep 2015 4429 18293 2739 25803 51263 59 41 3.8

Oct 2015 4955 16973 2448 25398 49774 61 39 2.1

Nov 2015 4223 11795 2119 14451 32587 57 43 1.6

Dec 2015 4305 10398 1451 14042 30196 61 39 1.3

Jan 2016 3845 9262 970 14632 28709 64 36 2.1

Feb 2016 2899 9394 946 12556 25795 60 40 1.6

Mar 2016 2545 9893 1246 13217 26902 59 41 1.1

Apr 2016 2222 10237 1078 13074 26611 57 43 0.1

May 2016 3263 13279 1341 18124 36006 59 41 0.8

TOTAL 47005 165845 22059 224615 459523 -- -- --

AVERAGE 4273 15077 2005 20420 41775 59 41 5

Gross Vehicle Weight

Month GVW NB Passing Lane GVW NB Driving Lane

GVW SB Passing Lane GVW SB Driving Lane Total GVW Kips

Jul 2015 1118825 1329524 894706 1876591 5219645

Aug 2015 1085997 1342758 912615 1805877 5147248

Sep 2015 1142972 1444392 982939 1917849 5488153

Oct 2015 1145988 1475556 986552 1932247 5540343

Nov 2015 1259076 1738435 1107567 2293540 6398618

Dec 2015 1662757 2466256 1915613 3708492 9753118

Jan 2016 1511192 2154132 1725874 3408929 8800126

Feb 2016 1358943 1926248 1583743 3091856 7960790

Mar 2016 1375343 1951286 1601751 3107761 8036140

Apr 2016 1183707 1519677 1075186 1923952 5702521

May 2016 1192123 1477892 1036387 1948500 5654903

TOTAL 14036923 18826156 13822933 27015594 73701606

AVERAGE 1276084 1711469 1256630 2455963 6700146

Overweight Vehicles

Month Total Number of Overweight Vehicles

Overweight / Total Volume

Overweight / Heavy Commercial Volume

Number Over 88,000 lbs

Number Over 98,000 lbs

Jul 2015 20102 1.5 23 3612 369

Aug 2015 12021 1 14.9 1485 259

Sep 2015 6992 0.6 9.2 424 140

Oct 2015 5254 0.4 6.7 297 119

Nov 2015 2650 0.3 4.9 159 62

Dec 2015 2327 0.3 4.5 123 50

Jan 2016 2288 0.3 4.7 161 56

Feb 2016 1522 0.2 3.2 124 33

Mar 2016 1159 0.1 2.3 55 18

Apr 2016 943 0.1 1.9 29 16

May 2016 2841 0.3 4.6 129 52

TOTAL 58099 -- -- 6598 1174

AVERAGE 5281.7 0.5 7.3 599.8 106.7

Freight Month NB Freight Tons SB Freight Tons Total Freight NB Freight % SB Freight %

Jul 2015 370290 414887 785177 47.2 52.8

Aug 2015 294847 355849 650696 45.3 54.7

Sep 2015 255383 310195 565578 45.2 54.8

Oct 2015 262191 320717 582908 45 55

Nov 2015 197989 193264 391253 50.6 49.4

Dec 2015 172532 178868 351400 49.1 50.9

Jan 2016 157840 175722 333562 47.3 52.7

Feb 2016 154981 162656 317637 48.8 51.2

Mar 2016 159573 173830 333403 47.9 52.1

Apr 2016 163395 170002 333397 49 51

May 2016 202590 231856 434446 46.6 53.4

TOTAL 2391611 2687846 5079457 -- --

AVERAGE 217419.2 244349.7 461768.8 47.4 52.6