Heavy Commercial Volumes at Selected Piezo and Wim Sites(2004-2011) Minnesota Department of Transportation Traffic Forecast and Analysis Section April 2012
\
Piezo and WIM Analysis Piezos record vehicle classification data 24 hours a day and 365 days a year. Automatic Traffic Recorders (ATRs) continuously collect hourly traffic data at various sites in Minnesota. Products from this data are Monthly ATR reports, Annual ATR Reports, historical Annual Average Daily Traffic (AADT), and adjustment factors for adjusting short duration counts. Automatic Vehicle Classifiers (AVC, Piezo) can be considered ATRs that collect classification data and are used to develop seasonal adjustment factors for adjusting short-duration classification counts. Weigh-In-Motion (WIM) is a type of ATR that also has sensors to collect weight data along with volume, axle spacing, length, speed, and vehicle type data. Data is recorded at continuously operating traffic volume stations, classification volume stations, and WIM stations located on the state s interstates, trunk highways, county state aid highways and municipal state aid streets. Currently, there are 70+ active devices maintained by MnDOT throughout the state-- 30+ in the sevencounty metro area and 35+ in greater Minnesota. Four categories of ATRs produce different data. ATR 1 produces total volume, ATR 2 produces speed and volume, ATR 3 produces volume, speed, and class, and ATR 4 are WIMs that also produce weight. ATRs are on Interstates, U.S Trunk Highways, Minnesota Trunk Highways, and County State Aid Roads (CSAHs).. Since 2008, The Office of Transportation Data and Analysis (TDA) has been using monthly ATR data to produce a monthly ATR report. The purpose of the ATR monthly report is to monitor the most recent traffic conditions on Minnesota roads. ATR data also contributes to our understanding of design hour volumes. Such an understanding contributes to decisions made in designing roads. By analyzing these continuous counts over a period of years, one can get a sense of traffic and vehicle type patterns and trends for the entire traffic stream AADT. Our focus in this report is the truck component that makes up the portion of AADT known as HCAADT (Heavy Commercial Annual Average Daily Traffic). Any number of trends can be studied among these are change over time in heavy commercial distribution and volume by month, day and year. The following is an update of the tables and charts initially produced in the September 2009 report (Heavy Commercial Volume Trends at Selected Piezos (2004-2007) and builds upon that database to include additional WIMs and piezos. Piezo data has been collected with other selected first-time sites and is being added to our existing piezo database. Each year additional sites will be added to continually expand our piezo information database from which we hope to discern observable trends and long term patterns. Each piezo analyzed in this report is based on a full year of data. Where 365 days of data did not exist at any particular piezo, the data was interpolated based on previous days and months from the same piezo in the same year. For the newest study, no piezos with less than about 30 days of data missing were used and the majority of sites had only a few missing days. Thus, the data selected from the WIMs and piezos represents very little inclusion of estimated data for individual truck categories.
Any non piezos and WIMs that were not functioning, not working, or contained large amounts of incomplete data were not used in this report. That accounts for the variability of individual years of data reported at each site. It was important to get accurate data and keep the interpolation of truck categories to a minimum to insure complete and reliable reporting. The term AADT is the estimate of daily traffic on a road segment that represents the total traffic on a segment that occurs in a one-year period divided by 365. HCAADT is the estimate of daily heavy commercial traffic on a road segment that occurs in a one year period divided by 365. HCAADT is defined as all vehicles with at least two axles and six tires. A brief overview of each Piezo follows: Please note that most of the discussion includes two and three axle single unit trucks as well as five or more axle semi trucks. Those categories make up the largest percentage of trucks and cause the most damage on the roadway system. Three and four axle semis, as well as heavy trucks with trailers and the twin trailer categories do not comprise nearly the volumes of the other categories. A glance at the charts that accompany the piezos will reveal this trend.
WIM 26 I 35, Steele County, Ellendale, 3.5 miles north of TH30 north of Ellendale
WIM 29 US 53, St. Louis County, Cotton, 2.7 miles north of Cotton South of Virginia Problem with equipment in 2010 resulted in little usable data Although there are gaps between 2008 and 2011 in reported data for WIM29, the increase in two axle single unit trucks is substantial. Numbers of five plus axle semis have decreased slightly, while most other categories with the exception of Twins have increased in volume.
WIM 31 US 2, Polk County, East Grand Forks, 6 miles east of East Grand Forks Between 2009 and 2010, average daily total volume increased, but that increase was mostly passenger cars. Trucks declined, mainly in the 2 axle single unit category. There was a slight increase in the number of 5 plus axle semis. In 2011, there was a decrease in passenger vehicles and an increase in volume in virtually all truck categories.
WIM 33 US 212, Renville County, Olivia,.7 miles east of Olivia Between 2009 and 2010, total average daily total volume increased very slightly, and that increase was about 100 passenger cars and roughly the same number of 5 plus axle semis. Total trucks increased slightly with most categories other than 5 plus axle semis remaining constant. In 2011, little change occurred in average daily truck volume, with the exception of a decline in five plus axle semis and passenger cars.
WIM 34 TH23, Chippewa County, Clara City, 3.1 miles south of Clara City Between 2009 and 2010, average daily total volume decreased somewhat, and that decrease was fairly constant throughout all the truck categories.
WIM 35 US2, Beltrami County, Bemidji, 3.2 miles east of Bagley Average daily total volume remained fairly static between 2008 and 2009, with an increase in 2010. A significant increase in two axle single unit trucks occurred between 2008 and 2009, only to drop back to 2008 levels in 2010. A decrease in five axle semis took place between 2008 and 2009, with those numbers remaining unchanged between 2009 and 2010. Other truck categories remained virtually unchanged. In 2011 average daily total volume remained virtually unchanged while average daily truck volume increased slightly in most categories, with the largest increase in average daily truck volume in the two axle single unite category.
WIM 36 TH36, Washington County, Lake Elmo, 3.3 miles east of I-694 Average daily total volume remained fairly steady between 2009 and 2010 (only a slight increase). A small increase in two axle single unit trucks occurred between 2009 and 2010, while five axle plus semis remained virtually unchanged from 2009 to 2010. Other truck categories remained relatively constant. In 2011 most categories experienced no decrease or a slight decrease in daily truck volume. Average daily total volume also decreased slightly.
WIM 37 I-94 MINN ROAD Wright County, 6.6 Miles North of TH25
WIM 38 I 535 St Louis County, SW of MSAS149(Garfield Avenue), Duluth
WIM39 - TH43 Winona County, NE of MSAS 101, Winona Between 2010 and 2011, the average daily total volume decreased slightly, due to a decline in passenger vehicles, while all truck categories increased in average daily truck volume
WIM 40 TH52 Dakota County,.5 Mi N of CSAH14 (Southview Blvd), West St Paul Between 2010 and 2011, average daily total volume decreased as did average daily truck volume. The truck volume decreased at lower percent than passenger cars, thus reflecting in the slight rise of average daily truck percent from 2010 to 2011. Thus trucks were a bigger percentage of the total vehicles in 2011.
WIM 41 CSAH 14, Polk County, Crookston, 1.3 miles north of CSAH 45 south of Crookston AADT on CSAH14 is relatively low, with little change in average daily total volume and average daily truck volume between 2009 and 2011.
WIM 54 CSAH 1, Dodge County, West Concord,.5 miles south of CSAH24 west of West Concord AADT remained fairly steady between 2009 and 2010 (only a slight increase). No change in two axle single unit trucks occurred between 2009 and 2010, while five axle plus semis remained virtually unchanged from 2009 to 2010 (with a slight increase of 6 vehicles). Other truck categories remained relatively constant, with a very small amount of trucks on the route. In 2011, there was very little change from the previous years in both volume and percent of vehicle totals. \
WIM 56 CSAH 5, Cottonwood, Storden, 2.5 miles north ofth30 north of Storden 100 90 80 WIM 56 Yearly Heavy Commercial Volume Trends By Truck Type 70 60 50 40 30 55 2009 20 10 0 11 4 1 1 2 0 2axsu 3+axsu 3axsemi 4axsemi 5Plusaxsemi TrkTrlBus Twins 56 56 56 56 56 56 56
PIEZO 101 I 535, St Louis County, Duluth, North of Garfield Avenue AADT increased about six percent while heavy commercial traffic decreased slightly between 2008 and 2009. Most of the minor decrease in truck traffic occurred in the five plus axle semi category, with other truck categories remaining fairly constant. Construction in 2010 on I-35 caused a decrease in traffic. 1400 1200 PIEZO 101 Yearly Heavy Commercial Volume Trends By Truck Type 1000 1008 941 800 600 2008 2009 400 409 426 200 0 185 190 170 155 92 83 62 64 3 16 2axsu 3+axsu 3axsemi 4axsemi 5Plusaxsemi TrkTrlBus Twins 101 101 101 101 101 101 101
PIEZO 103 I 35 St Louis County, Duluth East of Central Avenue AADT and heavy commercial traffic dropped slightly between the years 2004-2007. The volume of single unit trucks has remained stable over the time period; however, the volume and percent of five plus axle semis slowly and steadily declined from a high average of 1637 in 2004 to 1334 in 2007. AADT was approximately 42000 in 2007 on this Interstate in Duluth. Lane closures and repairs in 2008 and 2009 (July and August) resulted in lower traffic and thus data was not used for those years. In April 1, 2009 lanes one and two were not working for classification. More recent data was not used due to pavement repairs and lane closures in July and August of 2008 and 2009. In 2010 sensors were destroyed by construction. 1800 1600 PIEZO 103 Yearly Heavy Commercial Volume Trends By Truck Type 1637 1619 1493 1400 1334 1200 1000 800 600 635 641 641 597 2004 2005 2006 2007 400 371 341 331 330 200 0 31 27 26 148 124 126 120 57 54 47 25 42 26 27 30 2axsu 3+axsu 3axsemi 4axsemi 5Plusaxsemi TrkTrlBus Twins 25 103 103 103 103 103 103 103
PIEZO 175 I 94 - Stearns County, Sauk Centre, SE of CR 186 SE of Sauk Centre AADT dropped steadily from 2004 to 2009 while the heavy commercial percent increased slightly. Overall total truck volume remained virtually unchanged. The heavy commercial percent averaged around 20% over the measured time period. Five plus axle semi traffic decreased while two axle single unit truck volumes increased. The truck trailers and bus category increased steadily from 2004 until 2009 both in percent and volume. 2010 data was not used to due to incomplete months. In 2011, average daily truck volume decreased significantly in the two axle single unit category. From 2004 onward, that category has shown to widely fluctuate from one year to the next. Five plus axle semis decreased slightly in average truck volume while four axle semis increased somewhat. Other categories showed little variability from 2009 to 2011. The average daily volume of four axle semis increased between 2009 and 2011.
PIEZO 179 US 59 Lyon County, Garvin, SE of CR186 SE of Sauk Centre AADT on this trunk highway averaged about 2100 over the six year period from 2005 through 2010. AADT has remained virtually unchanged, while the percentage of heavy commercial trucks rose each year until a drop in 2009-2010. Total heavy commercial volume has gradually increased about 1% per year since 2005 but decreased in 2009 remaining unchanged through 2010. Individual truck category volumes remained virtually constant throughout the six years of reported data. In 2011, little has changed over time at this piezo. One glance at the chart elow indicates little change in total volume and truck volume since 2005, other than the drop in five plus axle semis between 2008 and 2009.
PIEZO 187 US 10, Benton County, Rice, 1.7 mile north of Jct. of CSAH31 and TH10 Between 2009 and 2011, there was a decrease in average daily truck volume and average daily total volume at this site. Overall, the numbers of trucks by categories fluctuated slightly, with the number of five axle plus semis decreasing at a larger rate than other truck categories. The average daily truck percent changed little the previous two years.
PIEZO 191- I 35, Chisago County, Wyoming, 1.4 Miles north of CSAH22 (East of Viking Blvd) There was minor fluctuation in AADT between 2008 and 2010. During the three year period, heavy commercial trucks varied by about 1%. There was a spike in the two axle single unit category between 2008 and 2009, and then a sudden decrease back below 2008 levels. The five plus axle semi category fluctuated within a narrow range of about 100 trucks per day between 2008 and 2010.
PIEZO 197 TH 60, Watonwan County, St James,.7 Mi W of W Jct. TH4 SW of St James AADT increased slightly between 2006 and 2007 with the percent of heavy commercial trucks remaining virtually unchanged. Single unit truck volume increased slightly while five plus axle semis declined from 744 to 724 over the two year period. 1000 900 800 700 PIEZO 197 Yearly Heavy Commercial Volume Trends 744 724 600 500 400 2006 2007 300 200 100 0 118 89 61 40 32 39 35 17 21 21 13 10 2axsu 3+axsu 3axsemi 4axsemi 5Plusaxsemi TrkTrlBus Twins 197 197 197 197 197 197 197
PIEZO 198 US 212, Renville County, Granite Falls, E of TH23 West of Sacred Heart AADT decreased slightly between 2004 and 2007 but spiked upward in 2008, with the heavy commercial percentage increasing slightly each year (2004-2008), from 16.2% and 18.3%. While the heavy commercial truck percentages increased slightly, the volume of single unit trucks changed little. The five plus axle semi volumes were unchanged until 2008, which increased by 66, from 298 to 364. Year 2009 data was not reliable due to more than 50% imputed data in one direction and inadequate October data. In 2010, there was a decrease in traffic due to construction on TH212. The gap between 2008 and 2011 reported data has shown an increase in all truck categories (except the Twins category) in average daily truck volume and average total volume. Most increases were modest, with the numbers of five plus axle semis being the highest since 2004.
PIEZO 199 US 75, Pipestone County, Pipestone,.5 Mi N of CR69 N of Pipestone AADT averaged about 1375 over the four year period through 2008. AADT never varied by more than 25 total vehicles. Heavy commercial percent fluctuated somewhat, averaging about 15.7% during the four year period with a high of 17.6% and a low of 14.3%. Two axle single unit truck volumes varied during this four year period with the 2008 volume of 37 the lowest in four years. A small but steady increase occurred in the five plus axle semi category. Year 2009 data was incomplete due to a lack of about two months data. 200 180 160 PIEZO 199 Yearly Heavy Commercial Volume Trends By Truck Type 140 120 125 122 115 107 2005 100 2006 80 60 40 20 0 46 64 39 37 16 26 19 19 16 14 14 15 14 8 8 8 9 10 9 6 0 0 0 2axsu 3+axsu 3axsemi 4axsemi 5Plusaxsemi TrkTrlBus Twins 1 2007 2008 199 199 199 199 199 199 199
PIEZO 204 US 169, Mille Lacs County, Onamia,.3 Mi. N. of CSAH22 S. of Onamia The AADT between 2004 and 2009 fluctuated slightly, with about 1200 fewer vehicles in 2009. 2010 brought an increase back to 2007 levels. Heavy commercial total truck volumes remained unchanged between 2009 and 2010. Over the six year time period, there was a fairly minor decrease in five plus axle semis volumes between 2004 and 2010. Two axle single units have remained constant, with the exception being an increase in 2007. In 2011 average daily truck volume decreased slightly for most categories, or remained virtually the same. Average daily total volume changed little from 2010. The overall trend for five plus axle semis has been downward modestly since 2004.
PIEZO 212 TH 14, Olmsted County, Rochester, E of CR104 (60 th Ave NW), W of Rochester
PIEZO 213 TH 61, Lake County, Two Harbors,.5 Mi SW of CR103 SW of Two Harbors Over a five year period from 2004 through 2008, AADT dropped 11% from 7900 to 7100, while the heavy commercial percent dropped about 1.3% over the same time frame (7.4% - 6.1%). The volume of two axle single units dropped in four of the five measured years, while the five plus axle semi volume decreased every year. In 2010 there was a decrease of traffic in July and August due to construction and the data was not used 400 350 PIEZO 213 Yearly Heavy Commercial Volume Trends By Truck Type 323 300 268 250 200 150 176 166 170 159 123 237 228 207 2004 2005 2006 2007 2008 100 50 0 47 37 40 38 36 38 32 35 25 25 17 19 9 4 3 7 10 14 7 6 0 0 1 1 2axsu 3+axsu 3axsemi 4axsemi 5Plusaxsemi TrkTrlBus Twins 2 213 213 213 213 213 213 213 `
PIEZO 219 US 2, Itasca County, Warba, 1.1 Mi NW of TH65 SE of Warba Between 2004 and 2007, the AADT dropped by approximately 1000 vehicles (or 27%) from about 3900 to 2900. AADT then increased from 2008 to 2010. Heavy commercial percent has remained steady over the period from 2004 through 2010 averaging around 13.5%. The trend in 2 axle single unit trucks, as well as 5+ axle semi trucks shows a steady decrease from 2004 to 2007, with a slight increase in both vehicle types in 2008 to 2010. Year 2009 data was not reliable or incomplete as several months of data failed to record. In 2011, the average daily truck volume has remained steady from the previous year, with slight decreases in most categories. The five axle plus semi category has fluctuated the most reaching a high in 2004 of 375 and a low of 247 in 2007.
PIEZO 220 US 71, Hubbard County, Park Rapids, S of CR89 N. of Park Rapids Five years of data shows a steady increase in heavy commercial percent from 2005 to 2009 (12%- 14%) then a sharp decrease back to 2005 levels in 2010. AADT increased between 2007 and 2008 and then leveled off in 2009 and 2010 still lower than the AADT in 2005. Two axle single unit truck volumes and five plus axle semis have fluctuated since 2005. Total trucks are less than they were in 2005. From to 2010 to 2011, there was little change in average daily truck volume and average daily total volume. Five plus axle semi volumes have fluctuated somewhat until 2009, with a steady rise in volume through 2011. A spike in 2 axle single unit volume in 2009 has shown to be somewhat of an anomaly.
PIEZO 221- TH 34, Hubbard County, Nevis, 1.5 Mi NE of CSAH2 NE of Nevis AADT has increased between 2007 and 2010 after having dropped between 2005 and 2007. Between 2005 and 2008, heavy commercial percentage dropped, but increased in 2010, as did volumes. Two axle single unit truck volume fluctuated between 2005 and 2008 but increased to their highest levels in 2010. The number of five plus axle semis slowly decreased from 2005 to 2008 then also increased in 2010. Year 2009 data was not reliable or incomplete as it contained several bad months of data.
PIEZO 223- TH 371, Cass County, Walker, 1.2 miles south of TH200 south of Walker 150 130 110 Piezo 223 Yearly Heavy Commercial Volume Trends By Truck Type 90 84 88 70 2009 50 36 30 20 10 11 10 5-10 2axsu 3+axsu 3axsemi 4axsemi 5Plusaxsemi TrkTrlBus Twins 223 223 223 223 223 223 223
PIEZO 225 - TH 210, Ottertail County, in Battle Lake, 2.1 miles west of CSAH47 W of Battle Lake AADT and heavy commercial percent increased slightly each year from 2008 through 2010, with all truck categories varying slightly.
PIEZO 227 I 90, Freeborn County, Albert Lea, 1.5 miles west of TH13 NW of Albert Lea Two successive years, 2004 and 2005, resulted in a slight decrease in AADT and a slight increase in heavy commercial percentage. A glance at the graphics shows a consistent average volume of five plus axle semis with only a variance of 50 vehicles from one year to the next. Other heavy truck types remained basically unchanged. Year 2009 data was incomplete, with only 174 days of class data recorded. In addition, 2010 data was invalid until August of 2010. In year 2011, complete data in the intervening six years shows a slight increase in several truck categories, with the average daily truck volume increasing while the average total volume decreasing. A steady increase in five plus axle semis occurred between 2004 and 2011, while two axle single unit trucks declined. The average daily truck percentage has increased slowly during this time frame.
PIEZO 341 I 694, Washington County, Oakdale, south of CSAH35(50 th St) in Oakdale 2011 data at this site was not accurate or complete enough for inclusion into the database 4300 3800 3300 Piezo 341 Yearly Heavy Commercial Volume Trends By Truck Type 3078 2800 2300 2009 1800 1300 800 300 901 341 214 397 137 88-200 2axsu 3+axsu 3axsemi 4axsemi 5Plusaxsemi TrkTrlBus Twins 341 341 341 341 341 341 341
PIEZO 352 - US 10, Anoka County, Ramsey, Daytonport scale in Ramsey Between 2008 and 2010, AADT dropped each year, along with a decrease in 2 and 3+ axle single unit trucks. During the three year period, 5+axle semis fluctuated (decreasing from 2008 to 2009, and then increasing slightly in 2010). Other categories changed little during the three year period. A glance at the below graph reveals a few trends, namely the slow but steady decline in average truck volume in the two axle and three plus axle single unit trucks as well as tractor trailers/buses. The semi truck categories bounce around with the five plus axle semi category at its lowest point in average daily volume since 2008. 2011 shows a consistent decrease in 2 and 3+ axle single unit trucks. There was a decrease in 5+ axle semi trucks, as well as a reductions in AADT, average daily truck percent, average daily total volume and average daily truck volume
PIEZO 353 US 169, Scott County, Jordan, SW of CR59 SW of Jordan Five years of data between 2004 and 2009 indicated that AADT fluctuated somewhat and the heavy commercial percent remained relatively stable varying by only about one percent (9.8-10.6%). Five plus axle semis fluctuated during the five year period peaking at 1600 in 2005, and dropping steadily by almost 400 through 2009. Between 2007 and 2008, two axle single unit trucks increased by about 75 (after having fluctuated in prior years). They remained virtually unchanged between 2008 and 2009. In 2010, there was a decline in volume in all truck categories except three plus axle single units. Conversely, 2011 showed a reverse in this trend, with an upward tic in virtually all truck categories. Five plus axle semis peaked in 2005 and have been declining steadily until 2010, with an increase in average daily truck volume in 2011.
PIEZO 381 - US 212, Carver County, Cologne, 1.7 mile west of CSAH51 west of Cologne Between 2008 and 2010 there was a 15% increase in AADT and significant increases in every individual truck category - including 2 axle single units (13%) and 5+axle semis (18.5%). Only twin trailers remained constant between 2009 and 2010. In 2011, most truck categories declined in average daily truck volume. Also, average daily total volume declined marginally.
PIEZO 388 US 8, Chisago County, Forest Lake 1 Mi N of TH61 N of Forest Lake Five years of data revealed a slowly declining AADT(with the exception of 2009). The heavy commercial truck percentage changed little over the period from 2004-2010 (averaging around 4-5 percent). There was a spike in four axle semis in 2006 followed by a gradual reduction through 2010. The total number of 2 axle single units and 5+ axle semis has moved within a narrow range over the five year timeframe with a gradual reduction in 5+ axle semis since 2005. In 2011, there was a decline in overall average daily truck volume and average daily total volume. A steep decline in five plus axle semis occurred between 2010 and 2011, as well as decline in three plus axle single unit trucks. Both three and four axle semis increased volume significantly between 2010 and 2011.
Location of Piezos and WIMs used in this report
SUMMARY Piezo data has been and continues to be analyzed on a monthly basis in addition to the annual summaries described above. We have analyzed piezo data on a monthly basis to determine seasonal adjustment factors for each vehicle type by analyzing Monday through Friday data. Vehicle classification counts are typically taken on weekdays in the months from April through October. The factors derived from an analysis of piezo data are used to adjust vehicle classification counts to HCAADT which are then used in MnDOT s traffic forecasting process. In addition, factors determined in rural and urban areas of the state are used to develop different factors to adjust heavy commercial data collected from short duration classification counts. Several piezo sites have been added in recent years and our plan is to convert all of our ATR s to piezo sites in the coming years. This will increase our understanding of truck patterns throughout the state and enable us to effectively maintain, manage and monitor truck travel on the trunk highway system throughout Minnesota. The vehicle-miles of travel has been increasing for decades in Minnesota, but since the year 2004 traffic has remained at about the same level. In recent years, the highest growth in VMT in Minnesota has been in the counties surrounding the Twin Cites while the growth has slowed or declined on many of the rural counties. The VMT in Minnesota has been slightly declining from 2007 to 2010. Due to factors such as the economic environment, we anticipate, at least in the near-term that VMT will continue to decrease, but at a more moderate rate than Minnesota has seen over the past decades. An analysis of the selected piezo data in this report has indicated a stability in heavy truck numbers at most sites between 2004 and 2007. Between 2007 and 2008, there was no consistent pattern regarding increases or decreases in AADT, five plus axle semi volumes or heavy commercial percentages. Overall, between 2007 and 2008 most of the selected piezos increased in heavy commercial percent, while about half increased and half decreased in AADT and five plus axle semi volumes. In 2009, there were nine piezos and one WIM that were compared to 2008 data. The results, shown in the table below, indicate no discernible pattern or connection between AADT growth and heavy commercial percent growth. Trend analysis is only useful at individual piezo sites. Appendix 1 shows that between 2010 and 2011, there was a decrease in average daily total volume and average daily truck volume at selected piezo and wim sites. Seven sites showed an increase in truck volume, while just two sites increased in total volume. Please note that while percentages may increase or decrease at a higher rate, the wide disparity between total volume at sites may show larger swings for smaller AADT locations thus giving the appearance of larger actual volume changes. A glance at the volume numbers shown on the following two appendix tables will reveal this. Appendix 2 shows a sum total of average annual percent change of all selected sites from the beginning of the series of reports on Piezo and Wim sites. The change is annualized depending on the number of years of complete data. Thus, for example, two years of data versus seven years of data provides a similar annual percent change. Usually, larger volume sites have smaller percentage
swings. Since, 2005, of the 30 plus sites analyzed for this study, the majority of sites have decreased over time in total volume percent change, total truck volume percent change, and total five plus axle semi percent change. It is pretty impossible to make sweeping assumptions regarding vehicle change on Minnesota s roadways. However, the user of this report can get a pretty good feel what the volume of auto and truck activity has been over time at the selected Piezos and Wims shown in this report Summary Data Appendix 1
Summary Data Appendix 2 If you have any questions on the information presented here, please contact Mark Levenson at 651 366 3862 or Thomas Nelson at 651-366 3868