Trends in North Carolina s County Road Conditions,

Transcription

1 Trends in North Carolina s County Road Conditions, By David T. Hartgen, Ph.D., P.E. Professor of Transportation Studies University of North Carolina at Charlotte Charlotte, North Carolina December 8, 2004 A Report Prepared for the John Locke Foundation 200 West Morgan, Suite 200 Raleigh, North Carolina Copyright 2004 by the author Permission is given to copy and reproduce by electronic or paper with appropriate credit.

2 Acknowledgements This report was prepared by Professor David T. Hartgen, University of North Carolina at Charlotte, under a grant from the John Locke Foundation, Kory Swanson, Vice President of John Locke Foundation,provided administrative guidance for the study. M. Greg Fields, a graduate student in geography at UNC Charlotte, assisted in the preparation of the data files, maps, and tables; his assistance is gratefully acknowledged. The North Carolina Department of Transportation provided access to the pavement condition files used in this analysis. The Federal Highway Administration provided data on North Carolina s bridges. The views expressed in this report are solely those of the author and do not necessarily reflect the views of the sponsor or these agencies or individuals. About the Author David T. Hartgen, Ph.D., P.E. is Professor of Transportation Studies at the University of North Carolina at Charlotte, where he established the Center for Interdisciplinary Transportation Studies and now teaches and conducts research in transportation policy. He is the author of about 324 papers and reports on a wide variety of topics in transportation policy and planning, is US Editor of the international journal Transportation, and is active in professional organizations, particularly the Transportation Research Board. He is a frequent media interviewee in local and national publications. Before coming to Charlotte in 1989 he was a Transportation Planner with the New York State Department of Transportation and a policy analyst at the Federal Highway Administration. He holds engineering degrees from Duke University and Northwestern University, has taught at SUNY Albany, Union University, Syracuse University and lectures widely. He is an Adjunct Scholar at the John Locke Foundation. He can be contacted at dthartge@ .uncc.edu, or by telephone at His website is 2

3 Contents Abstract 4 I. Introduction 5 A. Issues 5 B. Methodology 5 II. Findings 9 A. Overall Trends 9 B. Pavement Condition Trends in Pavement Condition Trends by County Geography of Trends 13 C. Lane Widths Trends in Narrow Lanes Trends by County Geography of Trends 20 D. Shoulder Widths Trends in Narrow Shoulders Trends by County Geography of Trends 24 E. Bridge Decks Trends in Bridge Deck Condition Trends by County Geography of Trends 28 III. Conclusions and Recommendations 30 A. Conclusions and Discussion 30 B. Recommendations Policy Actions Funding Actions Technical Steps 35 Appendices 37 A. NC Road Conditions by County 38 B. NC Roads with Narrow Lanes by County 40 C. NC Roads with Narrow Shoulders by County 42 D. NC Bridge Decks in Poor or Worse Condition by County 44 E. NC Road Mileage and Bridges by County 46 3

4 Trends in North Carolina s County Road Conditions, Abstract: A uniformly high-quality road system is critical to North Carolina s economic health and to the efficient activities of its citizens, businesses and visitors. This study reviews the condition of state-owned roads in each of North Carolina s 100 counties over the period , and bridge decks from 1998 to Four indices of road and bridge status (poor-rated pavement, narrow lanes, narrow shoulders, and poor-rated bridge decks) are computed for each county and for the state s 14 highway divisions. The source of the data is the state s detailed road and bridge inventories. The geographic patterns of the 100 county ratings are then examined. North Carolina s percentage of poor-pavement mileage worsened from 7.92 percent in 1998 to 8.87 percent in 2002, then improved slightly to 8.19 percent in Over the 6-year period, the mileage of poor-condition pavements is increasing at a rate about 93 miles per year. The percentage of narrow lanes has only marginally improved since 1998, and the percentage of narrow shoulders has worsened. Only the percentage of poor-rated bridge decks has substantially improved. The State s 100 counties vary widely in condition, with counties in the western mountainous regions reporting significantly higher percentages of narrow lanes and narrow shoulders. Pavement conditions also vary widely. The percentage of poor pavements varies from a low of 0.0 percent in Yancey County to a high of 27.2 percent in Ashe County. Pavement conditions were also worse in the state s western counties in 1998, but weather problems (Hurricane Floyd in 1999) resulted in recent deterioration of roads on the eastern side of the state. Changes in pavement rating procedures have made comparative changes in county conditions difficult to determine. The percentage of narrow lanes varies from a low of 39.9 percent in Mecklenburg County to a high of 93.0 percent in Alleghany County. The percentage of narrow shoulders varies from a low of 0.4 percent in Stokes County to a high of 71.3 percent in Surry County. On the other hand, bridge conditions appear to be more uniform throughout the state and have less variation: the percentage of poor bridge decks varies form a low of 0.0 percent in 6 counties to a high of 11.9 percent in Hoke County. The study concludes that highway funding formulas in conjunction with varying terrain have resulted in geographically unequal system. Specific policy goals should be established to improve the inequities in the state s road system by 2010 and that present funding formulas should be revised to achieve those goals. 4

5 I. Introduction A. Issues: North Carolina has the second-largest state-owned road system in the US, almost 79,000 miles. A study in 2000 for the John Locke Foundation 1 using data from 1998 showed that the system was in quite poor shape on key indicators. Almost 8 percent of pavements were rated in poor condition, 17 percent of shoulders were narrow, 74 percent of the system had less than 11-ft lanes, and 35 percent of bridges were rated deficient. Road conditions were also found to vary widely across the state s 100 counties, with the western and piedmont counties generally faring worse than eastern counties on most indicators. A more recent national comparison of road statistics put North Carolina in the bottom fifth of state road systems nationwide, 2 and showed a slow but steady slide in the condition of North Carolina s road system over the past decade. Data on the highest functional classes (Interstate and rural primary) also show sharp deterioration in recent years. Clearly, North Carolina is losing the battle on road conditions. In response, the State has taken some initial actions to increase road maintenance funds and has recently issued a long-range plan calling for major shifts toward maintenance. 3 However, no recent assessment of conditions by county has been conducted, so it is not possible to determine whether conditions are deteriorating everywhere, or whether some areas of the state are holding their own on key indicators. Hurricane Floyd in 1999 in eastern counties and Hurricanes Charles and Ivan in 2004 in western counties may also have substantially worsened roads. The purpose of this analysis is to update the earlier study by gathering and reporting on road conditions for each county and determining how conditions in each county have changed since Specifically, the goal of the analysis is to: 1. Determine the condition of state-owned roads in each of the 100 counties; 2. Determine changes in condition over time, and the reasons for these changes; 3. Recommend actions to reduce or reverse the deterioration of the system and remove inequities. B. Methodology The method used in this analysis is a straightforward summary of county-level information from large data files maintained by NCDOT. These files contain information 1 Hartgen D. On the Road Again: Performance, Needs and Funding Options for North Carolina s Highways. Policy Report for the John Locke Foundation, Raleigh NC 27601, October On the web at 2 Hartgen, D. The Looming Crisis in Highway Condition: Comparative Performance of State Highway Systems, , Report prepared for the John Locke Foundation, Raleigh NC 27601, February On the Web at 3 Charting a New Direction for NCDOT: North Carolina s Long-Range Statewide Multimodal Transportation Plan, NCDOT, Raleigh, NC 27699, September 2, Available at 5

6 on the condition and characteristics of the NC State-owned highway system and state and local highway bridges, for various years. The primary data sources are: 1. North Carolina s Highway Design Manual, 4 containing standards for lane widths, shoulder widths and other highway and bridge criteria. This manual is used to determine criteria for three key cut points : Poor-condition roads: roads rated less than 50 on NCDOT s biennial pavement condition surveys; Narrow lanes: roads with lane widths less than 11 feet. Although some modern roads (such as some subdivision roads) are occasionally built to less than 22-ft widths (<11-ft lanes), roads widened or improved would normally be widened out to 12-ft lane widths. Narrow shoulders: shoulders less than 4 feet in width. Although some roads, particularly in mountainous areas and within municipalities, might be constructed with less than 4-ft shoulders or with curb-and-gutter cross-sections, a 4-ft shoulder width is generally considered the minimum for most construction. 2. North Carolina DOT s Biennial Pavement Condition Survey, containing information on pavement condition and repair costs, lane widths, and shoulder widths for each road section. The survey covers 72,293 miles (year 2002) and 73,196 miles (year 2004) of state-owned road, but excludes the Interstate system 5. The source of the 1998 data is prior summaries prepared by the author, 2002 data transmitted by NCDOT, 6 and NCDOT s website-posted 2004 condition survey 7. The data is in MS Excel format, organized by road section, within route number, within county, within DOT Division. This file was then mined to isolate the data elements of interest: Overall road condition score, based on a rating developed from observing the incidence and severity of several distress symptoms, primarily cracking, rutting, bleedings, and joint condition. Repair costs, estimated by NCDOT based on the condition rating, section length, and number of lanes. These are based on NCDOT s 4 North Carolina Department of Transportation, Design Manual, NCDOT, Raleigh, NC 27706, January 1, 1978, as revised through The pavement condition of the Interstate System is measured using a different measure, pavement smoothness (International Roughness Index), which is reported annually to the Federal Highway Administration. 6 Correspondence from Mr. Matt Adams, Maintenance/Operations Staff Engineer for NCDOT Division 10, to Prof. David T. Hartgen, UNC Charlotte, March 8, 2004, and corresponding CD-ROM. 7 NC Department of Transportation, Raleigh, NC, 2004 Pavement Condition Survey, posted July On the NCDOT website, Data was obtained from the revised database posted September 5,

7 assessment of the most appropriate repair for the section, and unit costs for repairs drawn from recent NCDOT contract work records. Lane widths and shoulder widths, as measured in the field. These data were then categorized based on the standards noted above and summarized. It is important to understand what the pavement condition survey does not cover. First, it does not cover Interstates, which are surveyed using a different methodology based on pavement roughness. Second, the survey covers just state-owned roads, not most municipal streets, although State-numbered routes through municipalities are included. This means that for a given county the survey contains mostly information on roads OUTSIDE municipalities, in the donut areas surrounding the cities and towns, but not in the municipalities themselves or the Interstate system in those counties that have Interstate roads. The survey is therefore not a complete inventory of all roads in each county, but rather an inventory of the mostly suburban and rural roads in each county and those few state-owned roads that go through urban areas. Between 1998 and 2002, several potentially important methodological changes were made to the NCDOT pavement condition survey that may impact the comparisons described below. 8 One important change was to remove the prior survey s ratings from the field rating sheets. Before 2002 the road ratings for the prior survey were provided to the raters for reference in the field. However, beginning in 2002, ratings from the prior survey were not provided to the raters. This change was made to ensure that in-the-field assessments were not being biased up or down by knowledge of prior scores, a bias known as a testing effect. However, the suppression of prior scores also might lead to wider variations in ratings and possibly some wide swings in the ratings of individual sections. Secondly, several changes were made in the scoring of cracking distress and other symptoms. While not as radical, these changes might also affect the over-time variability of the ratings. Another issue is the accuracy of other data on the file. For instance, in reviewing the 2004 data on NCDOT s website in early September 2004, we noted large inconsistencies in the reported mileage for several counties, changes that more than doubled the reported mileage from prior years and therefore seemed unlikely to be accurate. These inconsistencies were brought to the attention of the NCDOT, which then undertook a complete review of the website data and made subsequent revisions to individual records in 8 counties. 9 It is this correct file (as of September 5, 2004) 10 which is the basis 8 Personal conversation between D. Hartgen and J. Blackwelder, Pavement Engineer, NCDOT, Raleigh, NC, August 19, Major changes to Ashe, Burke, Granville, Guilford, Lincoln, Person, Randolph and Surry County data. Posted on the NCDOT website September 5, The assistance of NCDOT s Pavement Management Section, particularly Mary Opperman, is appreciated in reviewing and revising this file. 7

8 of this report. However, given the pervasiveness of the corrections to just one key data item (section length), the possibility that other errors remain cannot be discounted. 3. North Carolina s 2002 Bridge Inventory, as compiled by the Federal Highway Administration from information submitted by NCDOT. This file, the latest available, contains data on the condition of the bridge decks for each of the 22,244 bridges in the state. It is conducted every other year by NCDOT inspectors, following carefully prescribed rating methods and a detailed field manual. The source of the file is a transmittal from the Federal Highway Administration 11 which provided the data in MS Access format. The bridge inventory was then mined to isolate the data elements of interest: Bridge deck, substructure, and superstructure condition data, as determined from the Recording and Coding Guide for the Structure Inventory and Appraisal of the Nation s Bridges 12, were extracted from the total data file. Bridge condition is measured on a 9-point scale, on which bridges rated 4 or less are described as being in poor condition. The extracted bridge data were sorted by county, based on county FIPS (Federal Information Processing Standards) codes and NCDOT Division (NCDOT administrative region within the state). Once obtained, the 2002 and 2004 data described above were then summarized and merged with similar information from Comparisons by county were then prepared in MS Excel format. Most counties showed slight increases in total mileage and total bridge counts; a few showing declines were investigated and the data were revised or retained. Analysis of the data was straightforward. Key statistics (percentages of poor pavement, lane width, shoulder width and bridge decks) were computed for 1998, 2002 and The relative ranking (1-100) of each county on the 4 key indicators for 2004, 2002 and 1998 was then determined, along with changes in each index for each county. Tables, maps, graphics, and text were then prepared describing the findings. 11 Transmittal from Ann Shemaka, Office of Bridge Technology, Federal Highway Administration, to Prof. David T. Hartgen, July 9, 2004 with corresponding CD-ROM. 12 Federal Highway Administration, Recording and Coding Guide for the Structure Inventory and Appraisal of the Nation s Bridges, Report FHWA-PD , US Department of Transportation, Washington, DC 20590, December p

9 II. Findings A. Overall Trends: The following table summarizes the overall finding of the study. The overall percent poor for each statistic for North Carolina is: Table II.1: Overall Trends in NC State-Owned Road Condition, Statistic Trend Percent poor pavement Worse Percent narrow lanes Slightly better Percent narrow shoulders Worsening Percent poor bridge decks Much better These findings are interpreted as follows: From 1998 to 2002, the percentage of poor pavement on North Carolina s stateowned roads worsened by almost 1 percent, from 7.92 percent to 8.87 percent. Conditions improved slightly to 8.19 percent in Over the 6-year period the State s poor-condition road mileage is increasing at about 93 miles per year. The percentage of roads with narrow lanes improved slightly, from 73.9 percent in 1998 to 72.9 percent in But since the number of miles surveyed increased, the number of miles with narrow lanes (less than 11 ft) actually increased by 2564 miles. From 1998 to 2004 North Carolina lost ground in reducing the backlog of narrowshoulder roads. The percentage of roads with narrow shoulders (less than 4 feet) increased from 16.0 percent to 19.8 percent from 1998 to Some of this increase may be due to revised measurements of shoulder widths, and in increasing mileage of subdivision roads with curbs and gutters. The percentage of bridges with poor-rated decks (4 or less on the federal 9-point rating scale) improved substantially, from 4.15 to 3.11 percent, or about 189 bridges. The following table provides more detail on these overall trends. 9

10 Table II.2: Details on Overall Trends, Item Change, Miles Surveyed Bridges Surveyed NA Poor Pavement, Miles Poor Pavement, Percent Narrow Lanes, Miles Narrow Lanes, Percent Narrow Shoulders, Miles Narrow Shoulders, Percent Poor Bridge Decks, Number NA Poor Bridge Decks, Percent NA In summary, the State s road system worsened on 2 of 4 key indicators, and improved slightly on another. On only one indicator (bridge deck condition) was a significant improvement reported. B. Pavement Condition 1. Trends in Pavement Condition From 1998 to 2004, the percentage of poor roads in the NC state highway system increased by about ¼ percent, from 7.92 percent to 8.19 percent. This corresponds to an increase of poor mileage at the rate of about 93 miles per year. The percentage of roads in good condition increased from to percent, and the percentage of roads in fair condition declined by over 3 percent, from to percent. Figure II.1 shows the overall trends. The State s fair-condition mileage has fallen and its good-condition mileage increased. Comparing 1998 to 2002, more mileage slid into the poor category, but between 2002 and 2004 this ominous trend seems to have been reversed. The figure shows that the State is having trouble keeping up with the slowly increasing backlog of poor-condition roads, even while it expands the road system and re-surfaces other roads to good condition. Time will tell whether the most recent trend of improving poor-pavement mileage holds up. 10

11 Figure II.1: State-Owned Roads by Pavement Condition, Percent of Total Road Miles % Roads-Poor Condition % Roads-Fair Condition % Roads-Good Condition Trends by County The State s 100 counties vary widely in percentage of poor pavement. Although the overall statewide percentage of poor pavement in 2004 was 8.19 percent, North Carolina s counties vary from as low as 0.00 percent poor pavement (in Yancey County) to as high as percent poor pavement in Ashe County. The Appendices provides a detailed listing of all 100 counties and their ratings. Over the past 6 years there has also been a significant shift in the location of poor-condition roads. Tables II.3 and II.4 show the top 10 and bottom 10 counties, in terms of the percentage of poor roads, for 1998, 2002 and In 1998 most of the toprated counties were from eastern North Carolina. But of the top 10 counties in 1998, only three held that honor in 2004, and only one (Hoke) was in the top 10 in all three years. And several counties that were rated in good condition in 1998 (Greene, Pitt) showed very large tumbles in their rankings in just four years. Conversely, several top-rated counties in 2002 (Rutherford, Lee) jumped significantly from lower ranks just four years earlier. By 2004, the top 10 included several newcomers from the middle of the state. 11

12 Table II.3: Top 10 Counties in Road Condition, RANK (1-100) County Pct Poor County Pct Poor County Pct Poor 1 Granville 0.05 Dare 0.00 Yancey Wilson 0.09 Anson 0.92 Richmond Greene 0.37 Moore 1.12 Caswell Pitt 0.49 Robeson 1.75 Wilson Hoke 0.53 Hoke 1.39 Hoke Scotland 0.66 Rutherford 1.61 Montgomery Davie 0.98 Halifax 2.11 Lee Robeson 1.04 Lee 2.15 Alleghany Beaufort 1.10 Carteret 2.19 Randolph Moore 1.11 Wilson 2.22 Scotland 1.16 (Newcomers in RED) A similar but geographically flipped pattern is also apparent for the worst-rated counties (see Table II.4). In 1998, most of the bottom 10 counties were located in western North Carolina, and Rowan County reported the highest percentage of poor-condition roads in the State at percent (Rowan was also the worst-rated county in 1996) 13. By 2002, the bottom-rated county was Forsyth, and Rowan had improved to 48 th statewide. Of the bottom 10 counties in 1998, 5 remained in the bottom 10 in 2002, but 5 improved and several (Rowan, Burke, Swain. Davidson) improved substantially. By 2004, the bottom 10 list contained both western and eastern North Carolina counties. Table II.4: Bottom 10 Counties in Road Condition, Rank County Pct Poor County Pct Poor County Pct Poor 100 Rowan Forsyth Ashe Burke Macon McDowell Macon Graham Pamlico Alamance Clay Bertie Ashe Alamance Sampson Orange Ashe Mitchell Graham Pamlico Duplin Jackson Duplin Nash Swain Catawba Greene Davidson Jackson Stokes (Newcomers in RED) 13 Douglas J. Orr and Alfred W. Stuart, Eds. North Carolina Atlas, University of North Carolina Press, Chapel Hill NC, 2000, p

13 3. Geography of Trends The wide variation in the condition of roads in North Carolina, and the large changes in the condition of a number of counties in just 6 years is not geographically random. Figures II.2, II.3 and II.4 show this data for 1998, 2002 and Figure II.2 shows that in 1998 the large variation in condition was east-west correlated, with eastern counties generally in considerably better shape than the western counties. Numerous explanations have been suggested for this wide difference and its geographic pattern, including soils and terrain, weather and climate, construction materials, differences in funding formulas, and politics, to name just a few. In our earlier assessment of condition, written in 2000, 14 we expressed concern about this pattern and called for its redress over time through a concerted effort to make conditions more uniform throughout the state. However, Figure II.3 shows that just 4 years later, in 2002, the strong geographic east-west pattern in road condition had largely disappeared, with many more counties in the eastern side of the state now rated below the state average. The later data show a mixture of good-condition and poor-condition counties throughout the state, but also some very sharp changes. A number of counties on the eastern shore and coastal plain previously rated in good condition were rated poor. These include (particularly) Brunswick, New Hanover, Duplin, Onslow, Jones, Crave, Beaufort, Hyde, and Northampton. At the western end of the state, some counties (Rutherford) worsened substantially while others improved (Swain, Alleghany). In the middle of the state several counties improved (Rowan, Davidson) while others worsened (Harnett). This pattern was largely repeated in Figure II.4 is similar in pattern to the 2002 map in that it shows a wide band of eastern NC counties on the coastal plain that now have greater than 10 percent poor pavement. But there also some important exceptions: several mountain counties (Cherokee, Graham, Macon) showed substantial improvements from 2002 to 2004, while several eastern counties (Currituck, Washington, Sampson) worsened substantially. Analysis of trends over the 6-year period reveals disturbing variations. Some counties reported wide swings in the percentage of poor roads over the 6 year period. For instance, the following table shows some of the largest changes: Table: II.5: Counties Reporting Large Changes in Percent Poor Pavement County 1998 (rank) 2002 (rank) 2004 (rank) Alleghany 7.83 (61) (83) 0.78 (8) Bertie 1.54 (17) (87) (97) Carteret 1.26 (11) 2.19 (9) 9.90 (63) Chowan 1.42 (13) 2.75 (16) (72) Forsyth (78) (100) 8.12 (49) Granville 0.05 (1) (84) (69) New Hanover 1.36 (12) (90) (67) Pitt 0.49 (4) 9.40 (56) (74) Rowan (100) 7.15 (48) 9.07 (56) Rutherford (83) 1.61 (6) 1.81 (16) Worsened Improved 14 Hartgen, 2000, op. cit. (see footnote 1). 13

14 Figure II.2: Percentage of Road Miles in Poor Condition, 1998 NC DOT Divisions are outlined in black and labeled in black ovals % Road Miles in Poor Condition 0.00 to to to to to to Source: NC DOT Miles NC Averages % % % Cartography by Greg Fields Figure II.3: Percentage of Road Miles in Poor Condition, 2002 NC DOT Divisions are outlined in black and labeled in black ovals % Road Miles in Poor Condition 0.00 to to to to to to Miles NC Averages % % % Source: NC DOT 14 Cartography by Greg Fields

15 Figure II.4: Percentage of Road Miles in Poor Condition, 2004 NC DOT Divisions are outlined in black and labeled in black ovals % Road Miles in Poor Condition 0.00 to to to to to to Miles NC Averages % % % Source: NC DOT Cartography by Greg Fields 15

16 On the other hand, other counties were stable in condition over the 6-year period: Table II.6: Counties Reporting Stable Road Conditions County 1998 (Rank) 2002 (Rank) 2004 (Rank) Ashe (96) (95) (100) Avery (86) (70) (88) Chatham 4.64 (38) 5.42 (35) 7.28 (45) Guilford 6.77 (54) 8.21 (51) (64) Wilson 0.09 (2) 2.22 (10) 0.42 (4) These patterns suggest that a variety of complex trends are occurring in the conditions of North Carolina s road system. The overall trend appears to be worsening conditions, brought on by a mixture of weather and climate, system age, traffic, and lower expenditures. However, on top of this overall trend are patterns of accelerated deterioration (most visible in the eastern coastal plain counties) exacerbated by major weather events, but system improvements (most visible in several mountain counties) and possibly changes in scoring procedures. Several explanations are possible for these wide variations and, perhaps even more important, the wide swings in condition for some counties. Among the possible explanations are: Repair efforts and funding differences. State funding formulas for secondary roads and for contract resurfacing are based partially on road repair needs, which are based partially on condition. In theory, these formulas push funds toward those counties that have the worst-condition roads, and once allocated to counties the funds (presumably) would be then spent on those roads needing work the most. This might explain some of the improvements in some low-rated counties (they would have received relatively more funds), and some worsening in the better-condition counties (they would have received relatively less funds). But it would not explain the improvements in some good condition counties or continued declines in other poor-condition counties. Time lags from the collection of data (1998) to its subsequent use in funding allocations (state fiscal year beginning 2000) and actual application to the pavement (2000 and 2001), combined with the relatively small size of the program, make it unlikely that the changes in condition in 2002 would have been caused by major repairs. Weakening overall state funding. Separate from repair strategies, several studies have found that North Carolina is not spending enough on repairs and maintenance of its road system. This concern was a major theme of the recently released Long-Range Statewide Transportation Plan. 15 This factor might be the cause of an overall underlying downward shift in state road condition. Maintenance and repair practices. Possibly, some Divisions have maintenance and repair strategies (project selection, materials, soils) or other circumstances that allow them to manage and maintain their road systems better, or conversely that lead to declines. 15 NCDOT, 2004, op.cit. 16

17 System age or traffic. Differences in system age, traffic volumes, truck traffic or other factors may lead to sharp declines in some counties but minimal changes in others. On the other hand, the above figures show that some of the state s most urban counties also have relatively good roads, suggesting that they might get more attention, are stronger, or perhaps just have newer roads. Hurricane Floyd and other weather events. The pattern of the condition changes between 1998 and 2002, particularly those in the eastern counties, suggests that major weather events such as Hurricane Floyd in 1999 resulted in major changes in the condition of roads that have still not yet been redressed. But obviously, these events would not explain sharp declines in some western counties. 16 Condition rating methods. NCDOT road ratings are conducted by its 14 divisions, which use field crews assigned to each county. Raters from the NCDOT s divisions and counties first attend training sessions and then field rate sections for practice. After training, each team then returns to its division and conducts the rating during the January- March time period. Results are then transmitted to the Main Office where they are edited and posted on NCDOT s website in the summer, about 4-6 months after the surveys. The basic rating method involves a careful drive-along of each pavement section, identifying the magnitude and severity of numerous distress symptoms such as cracks, ruts, bleeding, potholes, etc. The information is recorded on rating sheets that show each section s characteristics, but not the prior year s ratings. After traversing the section, which may range from a very short (0.1 mile) to long (3-5 mile) length, the rating team judges the magnitude and severity of each distress symptom and then proceeds to the next section. Sometimes the section is re-driven to check the assessment. Data sheets are then transmitted to the main office in Raleigh, where the data is entered into databases and the overall road rating is then developed. The main office also field checks some ratings, particularly those of new crews. Although structured and rule-based, the method is essentially subjective regarding the rating team s judgment of the magnitude and severity of distress. After the 1998 ratings were published, several reviews were made of possible variations in the scoring methods used by the road rating teams in different NCDOT Divisions. The possibility of wide variations in the procedures used by the individuals doing the scoring, which would lead to different ratings for a road depending on the scorer, raises the question of whether the whole rating system used by the NCDOT is accurate and consistent over time and is robust enough to be used for allocating funds. Table II.7 sheds some light on these possibilities by reviewing the poor-pavement data by NCDOT Division. Divisions on the eastern side of the state (Divisions 1-6) worsened steadily in road conditions during the 6-year period, while Divisions on the western side (Divisions 7-14) generally improved. However, one west-side Division (11, northwest corner) also worsened. This pattern suggests that perhaps weather-related factors such as Hurricane Floyd in 1999 may have precipitated the deterioration in roads in eastern NC which continued after 1999 and may even be accelerating today. 16 In September 2004 the state s western counties were hit with very large flooding problems from Hurricanes Frances and Ivan. Data collected in 2006 will, presumably, determine if these events had a similar impact on western North Carolina roads. 17

18 Table II.7: NC Division Roads in Poor Condition, 1998, 2002, and Change, Division Miles Poor % Poor Miles Poor % Poor Miles Poor % Poor Miles Poor % Poor Total (Divisions worsening in RED) The sharp east-west patterning of improvements and declines seems to have accelerated between 2002 and 2004, suggesting that good-condition roads were also weakened, putting them at risk for further deterioration in later years. C. Lane Widths 1. Trends in Narrow Lanes Figure II.5 summarizes the overall statewide trends for narrow lanes. Statewide, about percent of the state-owned highway system has lane widths that are less than 11 feet in width, about a 1-percent improvement over According to the NCDOT Highway Design Manual, 17 the general standard for lane widths for state-owned roads is 22 feet, or 11-ft lanes for most 2-lane roads. While the Manual allows for 20-ft roads (10-ft lanes) on some local roads and collectors, this is permitted only for roads with design speeds of 30 mph or less, most of which would be subdivision streets. For roads with higher design speeds, the standard of 22 feet applies except for low-volume (less than 400 daily traffic) roads. Higher functional classes (arterials and above) generally require 24-ft pavements (12-ft lanes). North Carolina has a large state-owned highway system in which most roads are in the lower functional classes. In addition, much of the system is on old alignment placed many years ago, before higher speeds and larger vehicle sizes became common. Therefore, the fact that almost ¾ of the system has less than 11 ft lanes should not be particularly surprising. On the other hand, it is well known in traffic safety that narrow rural lanes are a key factor leading to higher accident rates. Although it is clearly 17 NCDOT, Highway Design Manual, op.cit. 18

19 impractical for North Carolina to adopt a rigorous 11-ft or 12-ft rule for all lane widths, there should also be a concerted effort to widen narrow roads over time. That is why the small change in the state s lane width data is so disappointing. Over the past 6 years, the state has made only minimal progress in reducing the percentage of narrow lane roads on the state-owned system. Indeed as Table II.2 showed the actual mileage of less-than-11-ft roads has actually increased even though the percentage has fallen slightly. Figure II.5: Trends in Narrow Lanes, Narrow Shoulders and Bridge Decks Percent of Total Road Miles or Total Bridge % Narrow Lanes % Narrow Shoulders % Bridge Decks Poor Trends by County Contrary to the findings on pavement condition, the lane widths of North Carolina s state-owned road system have shown little change over the past 6 years. Table II.8 and II.9 show the rankings of the top 10 and bottom 10 counties, in terms of the percentage of narrow lanes, for Looking first at the best-rated counties, Table II.8 shows that the counties with the lowest percentage of narrow lanes are primarily the urban counties and some coastal counties. Recalling that the state road system consists of roads outside of municipalities (in the donuts of urban counties), more rapidly growing urban counties such as Mecklenburg would more likely have newer roads in the suburban donut ring areas between the municipalities and the county boundary, and these roads would more likely to have been built to wider widths. On the other hand, coastal counties typically have fewer topographical variations that would preclude wider roads being built initially. The bottom 10 counties with the highest percentage of narrow lanes (Table II.9) are exclusively western mountain counties, reflecting the difficulty and expense of building 22-ft roads in that terrain. The variation in percentage of narrow lanes is about a factor of 2, from a low of 41 percent in Mecklenburg County (Charlotte) to a high of 93 percent in Alleghany County, in northwest mountainous North Carolina. 19

20 There has been very little change in the ratings of these counties over the past 6 years. The tables show that with just a few exceptions the counties rated best or worst in 1998 have essentially the same ratings in 2002 and Although the individual ranks have shifted slightly, 9 of the top 10 counties and 9 of the bottom 10 counties are the same in 1998, 2002 and Table II.8: Narrow Lanes Top 10 Counties: Lowest Pct with < 11-ft Lanes Rank 1998 County % Narrow Lanes 2002 County % Narrow Lanes 2004 County % Narrow Lanes 1 Mecklenburg Mecklenburg Mecklenburg Cumberland New Hanover New Hanover Dare Dare Dare New Hanover Cumberland Cumberland Durham Forsyth Forsyth Brunswick Brunswick Brunswick Guilford Durham Durham Forsyth Guilford Guilford Carteret Carteret Carteret Scotland Martin Wilson (Newcomers in RED) Table II.9: Narrow Lanes Bottom 10 Counties: Highest Percent with < 11-ft Lanes Rank 1998 County % Narrow Lanes 2002 County % Narrow Lanes 2004 County % Narrow Lanes 100 Alleghany Alleghany Alleghany Ashe Ashe Ashe Yancey Mitchell Mitchell Yadkin Macon Macon Macon Wilkes Yancey Mitchell Yancey Clay Franklin Yadkin Polk Wilkes Polk Franklin Alexander Clay Wilkes Clay Alexander Alexander (Newcomers in RED) 1. Geography of Trends As noted above, the geographic pattern of this data is readily apparent from Figures II.6, Figure II.7 and Figure II.8, which show the distribution of counties by percentage of narrow lanes in 1998, 2002 and For each year, there is a strong tendency for the state s western mountainous counties to have a higher percentage of narrow lanes. But the relationship is not perfect since some eastern-shore counties, particularly in the northeast, also have a high percentage of narrow lanes. Over time, the geographic pattern of the state s narrow lane mileage has been remarkably stable. Only a few counties have changed their percentages of narrow lanes between 1998 and 2004, and these changes were generally less than 2 percentage points. 20

21 Figure II.6: Percentage of Road Miles with Narrow Lanes (< 11 ft. wide), 1998 NC DOT Divisions are outlined in black and labeled in black ovals % Road Miles with Lane Widths < 11 ft to to to to to to Miles NC Averages % % % Source: NC DOT Cartography by Greg Fields Figure II.7: Percentage of Road Miles with Narrow Lanes (< 11 ft. wide), 2002 NC DOT Divisions are outlined in black and labeled in black ovals % Road Miles with Lane Widths < 11 ft to to to to to to Miles NC Averages % % % Source: NC DOT 21 Cartography by Greg Fields

22 Figure II.8: Percentage of Road Miles with Narrow Lanes (< 11 ft. wide), 2004 NC DOT Divisions are outlined in black and labeled in black ovals % Road Miles with Lane Widths < 11 ft to to to to to to Miles NC Averages % % % Source: NC DOT Cartography by Greg Fields 22

23 Some of the apparent stability in these ratings may be due to measurement procedures. During the road rating process NCDOT crews may not spend time measuring lane widths and shoulder widths, particularly if there has been no change to the geometry of the road since the last survey. Since survey crews are provided with data on number of lanes and pavement width as part of the survey process, there would be no reason to remeasure pavement widths unless there had been a change in geometry. These considerations mean that the likelihood is high that road widths would not generally be changed during surveys. D. Shoulder Widths 1. Trends in Narrow Shoulders Overall, the percentage of roads with narrow shoulders worsened between 1998 and The percentage of roads with narrow shoulders less than 4 feet worsened substantially, from percent in 1998 to percent in We were unable to identify the basis for this abrupt change. Conversations with NCDOT indicate that no specific directions or highlights were provided to field crews regarding shoulder widths. 18 If the changes had been caused by some road widenings (taking footage from the shoulders) then one would have expected to see a change in the land width statistics as well. However, the largest changes in narrow-shoulder mileage occurred primarily in urban counties (Mecklenburg, Wake, Guilford, Cumberland, and Buncombe), suggesting that the increase in narrow-shoulder mileage was the result of increased suburban subdivision mileage (which often has narrow shoulders) and perhaps re-coding of urban sections based on their curb and gutter designs that have no shoulders. 2. Trends by County The following tables (Table II.10 and Table II.11) show the top 10 and bottom 10 counties, in terms of percentage of narrow shoulders, in 1998, 2002 and As with narrow lane widths, the percentage of narrow shoulders varies widely across the state s 100 counties, from as little as 0.38 percent in Stokes County to as high as percent for Surry County. Table II.10: Narrow Shoulders Top 10 Counties (Least Pct with <4 ft Width) Rank 1998 County % Narrow Shoulders 2002 County % Narrow Shoulders 2004 County % Narrow Shoulders 1 Stokes 0.13 Stokes 0.12 Stokes Sampson 1.11 Sampson 1.07 Caswell Pamlico 1.37 Lee 1.61 Pamlico Lee 1.50 Craven 1.67 Sampson Craven 2.02 Carteret 1.72 Pender Rockingham 2.29 Pamlico 1.75 Hoke Richmond 2.48 New Hanover 2.13 Lee Caswell 2.55 Caswell 2.46 Beaufort New Hanover 2.73 Beaufort 2.48 Craven Hoke 2.76 Hoke 2.55 Hyde 5.87 (Newcomers in RED) 18 Conversation with J. Blackwelder, NCDOT Pavement Management Section, September 16,

24 However, the counties have varied little in percentage of narrow shoulders over time. The tables show that the top10 and bottom10 counties have changed only slightly, with 9 of the top 10 and 9 of the bottom 10 being the same from 1998 to Table II.11: Narrow Shoulders Bottom 10 Counties (Highest Pct with <4 ft Width) Rank 1998 County % Narrow Shoulder 2002 County % Narrow Shoulder 2004 County % Narrow Shoulder 100 Surry Surry Surry Alleghany Alleghany Alleghany Avery Avery Avery Clay Mitchell Clay Macon Clay Mitchell Forsyth Yancey Forsyth Watauga Macon Yancey Yancey Wilkes Macon Catawba Watauga Wilkes Mitchell Madison Catawba (Newcomers in RED) There has also been a significant shift upward in the percentage of narrowshoulder roads in some of the top-rated counties. Although the county rankings themselves have not changed significantly, the percentage of narrow shoulders appears to have been re-calculated higher, possibly as a result of more careful measurement in the field. Interestingly, counties in the bottom 10 list have not shown the same trends. This data suggests that the apparent worsening of narrow shoulders between 2002 and 2004 is caused by more careful measurement in both urban and rural counties, along with increased suburban subdivision mileage in large urban counties. 3. Geography of trends Figures II.9, II.10 and II.11 show the geographic distribution of counties by percentage of narrow shoulders in 1998, 2002 and These maps show clearly that the narrow shoulder problem is largely one associated with the western counties, probably related to the steeper terrain and the difficulty of adding wider shoulders or building roads with adequate shoulders. With just one exception (Forsyth), all of the counties with higher percentages of narrow shoulders are located in the western mountainous region of the state. However, some western counties (Haywood, Henderson, Rutherford) also reported better-than average ratings. And a few counties on the eastern side of the state reported worse-than average results. These findings suggest that the narrow shoulder problem, while largely terrain-related, may also suffer from inaccurate measurement and some errors in reporting, and from increasing narrow-shoulder mileage in urban counties. Narrow shoulders are known to be a significant factor in accident severity and frequency, particularly on rural roads. On curves and in mountainous terrain, adequate shoulder widths provide a margin of safety in reducing the frequency of accidents and their severity when they do occur. North Carolina s high fatal accident rate 30% above the national average may be partially attributed to the fact that so much of the road system does not have these margins of safety built in. 24