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Home My WebLink AboutA-0009C Passing and Climbing Lanes Documentation 10_26_2020 Venture I 940 Main Campus Drive, Suite 500 Raleigh, NC 27606-5217 P 919.829.0328 To: Jimmy Terry, PE TGS Engineers 804-C N. Lafayette Street Shelby, NC 28150 Date: October 23, 2020 Project #: 38536.39 From: Andrew Topp, PE, PTOE Re: STIP Project No. A-0009C - Passing and Climbing Lane Justification Graham County, NC The above referenced project proposes to implement a 2+1 (alternating passing lanes) cross-section design along NC 143 and NC 28 in Graham County, NC. The construction of a 2+1 design will improve mobility along both corridors by allowing vehicles to efficiently pass slow moving vehicles and trucks while maintaining their direction of travel and minimizing crossings into the opposing lane of traffic. Table 1 identifies the proposed locations of the 2+1 design (locations based on Figures 1-4 in the Appendix) along with climbing lanes located on steep grades and characterizes elements that support the implementation of that design. As reported in the traffic analysis for this study, the improvements result in a corridor-wide average speed benefit of several miles per hour and improved reliability. Each direction and peak period experiences reliability benefits, however the largest improvement occurs the mountainous section between Cheoah and Stecoah. In this area, travel time variability reduces from 15 minutes in the No-Build condition to less than 8 minutes in the Build condition in the PM peak westbound direction due to the passing and climbing lanes installed. Table 1: Passing and Climbing Lane Justification Proposed Passing/ Climbing Lane Location Associated Figure # (Hydraulic Site No.) Reasons for Implementation Standards NC 143 SB Passing Lane (1,684 ft) Figure 1 (Site 3, 4)  Rolling terrain¹  Located in curve that diminishes sight distance²  Increased travel speed and reduced percentage time spent following3  AASHTO Green Book (Section 3.4.4) – Passing Lanes  Highway Capacity Manual (Chapter 15) NC 143 NB Climbing Lane (2,569 ft) Figure 1  Steep grade (approx. 4%)4  Increased travel speed and reduced percentage time spent following3  AASHTO Green Book (Section 3.4.3) – Climbing Lanes  Highway Capacity Manual (Chapter 15) NC 143 SB Climbing Lane (5,144 ft) Figure 1 (Site 5, 6)  Steep grade (approx. 3% and higher)4  Located in multiple curves2  Increased travel speed and reduced percentage time spent following3  AASHTO Green Book (Section 3.4.3) – Climbing Lanes  AASHTO Green Book (Section 3.4.4) – Passing Lanes  Highway Capacity Manual (Chapter 15) From: Andrew Topp, PE, PTOE Ref: 38536.39 October 23, 2020 Page 2 Venture I 940 Main Campus Drive, Suite 500 Raleigh, NC 27606-5217 P 919.829.0328 Proposed Passing/ Climbing Lane Location Associated Figure # (Hydraulic Site No.) Reasons for Implementation Standards NC 143 NB Climbing Lane (2,601 ft) Figure 2 (Site 7)  Rolling terrain and an opportunity to pass trucks before a series of curves4 5  Increased travel speed and reduced percentage time spent following3  AASHTO Green Book (Section 3.4.3) – Climbing Lanes  AASHTO Green Book (Section 3.4.4) – Passing Lanes  Highway Capacity Manual (Chapter 15) NC 143 SB Passing Lane (3,095 ft) Figure 2 (Site 8)  Sight distance is impaired due to curve²  Steep grade (approx. 3% and higher into curve)1  Increased travel speed and reduced percentage time spent following3  AASHTO Green Book (Section 3.4.4) – Passing Lanes  Highway Capacity Manual (Chapter 15) NC 143 NB Passing Lane (2,802 ft) Figure 2  Slight grade and rolling terrain¹  Located in curve that diminishes sight distance²  Increased travel speed and reduced percentage time spent following3  AASHTO Green Book (Section 3.4.4) – Passing Lanes  Highway Capacity Manual (Chapter 15) NC 143 SB Passing Lane (2,133 ft) Figure 3 (Site 9)  Opportunity to pass vehicles before a series of curves5  Increased travel speed and reduced percentage time spent following3  AASHTO Green Book (Section 3.4.4) – Passing Lanes  Highway Capacity Manual (Chapter 15) NC 143 NB Climbing Lane (11,299 ft) Figure 3 (Site 10)  Steep grade (8%) and located in a series of tight curves that diminish sight distance4  Climbing lane gives the opportunity to pass trucks and slow-moving vehicles5  Increased travel speed and reduced percentage time spent following3  AASHTO Green Book (Section 3.4.3) – Climbing Lanes  AASHTO Green Book (Section 3.4.4) – Passing Lanes  Highway Capacity Manual (Chapter 15) NC 143 SB Climbing Lane (10,075 ft) Figure 3  Steep grade (8%) and located in a series of tight curves that diminish sight distance4  Climbing lane gives the opportunity to pass trucks and slow-moving vehicles5  Increased travel speed and reduced percentage time spent following3  AASHTO Green Book (Section 3.4.3) – Climbing Lanes  AASHTO Green Book (Section 3.4.4) – Passing Lanes  Highway Capacity Manual (Chapter 15) From: Andrew Topp, PE, PTOE Ref: 38536.39 October 23, 2020 Page 3 Venture I 940 Main Campus Drive, Suite 500 Raleigh, NC 27606-5217 P 919.829.0328 Proposed Passing/ Climbing Lane Location Associated Figure # (Hydraulic Site No.) Reasons for Implementation Standards NC 28 WB Climbing Lane (6,724 ft) Figure 3 (Site 21, 22)  Steep grade (7%) and located in a series of tight curves that diminish sight distance4  Climbing lane gives the opportunity to pass trucks and slow-moving vehicles5  Increased travel speed and reduced percentage time spent following3  AASHTO Green Book (Section 3.4.3) – Climbing Lanes  AASHTO Green Book (Section 3.4.4) – Passing Lanes  Highway Capacity Manual (Chapter 15) NC 28 WB Passing Lane (1,487 ft) Figure 4  Steep grade (7%) and located before a major curve1  Passing lane gives the opportunity to pass slow-moving vehicles and vehicles turning off the mainline onto the smaller y-line roadways5  Increased travel speed and reduced percentage time spent following3  AASHTO Green Book (Section 3.4.4) – Passing Lanes  Highway Capacity Manual (Chapter 15) NC 28 EB Passing Lane (5,162 ft) Figure 4 (Site 24-26)  Grade (approx. 5%) and located before a series of curves¹  Passing lane gives the opportunity to pass slow-moving vehicles and vehicles turning off the mainline onto the smaller y-line roadways5  Increased travel speed and reduced percentage time spent following3  AASHTO Green Book (Section 3.4.4) – Passing Lanes  Highway Capacity Manual (Chapter 15) NC 28 EB Climbing Lane (2,221 ft) Figure 4  Steep grade (approx. 7%) and located in a curve4  Climbing lane gives the opportunity to pass slow-moving trucks and vehicles turning off the mainline onto the smaller y-line roadways and other destinations5  Increased travel speed and reduced percentage time spent following3  AASHTO Green Book (Section 3.4.3) – Climbing Lanes  AASHTO Green Book (Section 3.4.4) – Passing Lanes  Highway Capacity Manual (Chapter 15) 1 Where a sufficient number and length of passing sections cannot be obtained in the design of horizontal and vertical alignment alone, an occasional added lane in one or both directions of travel may be introduced to provide more passing opportunities. Such sections are particularly advantageous in rolling terrain, especially where alignment is winding, or the profile includes critical lengths of grade. (AASHTO Green Book – 3.4.4) From: Andrew Topp, PE, PTOE Ref: 38536.39 October 23, 2020 Page 4 Venture I 940 Main Campus Drive, Suite 500 Raleigh, NC 27606-5217 P 919.829.0328 2 The value of a passing lane is more obvious at locations where passing sight distance is restricted. (AASHTO Green Book – 3.4.4) 3 Within the passing lane, the average travel speed is generally between 8% and 11% higher than its upstream value and the percent time spent following is generally 58% to 62% of its upstream value. Within the climbing lane, there is a 7% improvement in ATS and 80% improvement in PTSF. (Highway Capacity Manual – Chapter 15, Part 4) 4 Adding a climbing lane for an upgrade on a two-lane highway can offset the decline in traffic operations caused by the combined effects of the grade, traffic volume, and heavy vehicles. (AASHTO Green Book – 3.4.3) 5 Passing lanes can also be provided to improve overall traffic operations on two-lane highways by reducing delays caused by inadequate passing opportunities over significant lengths of highways. (AASHTO Green Book – 3.4.4) $# $#$#$# $# $# $# 4 î îî 89:s î î î 44 î ï ï ï £¤129 £¤129""143 £¤129 £¤129 ""143 Old MotherChurch andCemetery RobbinsvilleFirst BaptistChurch The Hut Frank & LenoraColvard House ColvardMotorCompany Mattie & JohnColvard House ColvardHouse J. BoydCrisp House Delmas &Mary RuthShuler House WF WG WH WJ WL WQSKSD SG S F SHS E SLPigpenBranch Pi gpenBr anchSJSP S I SFE SweetwaterCreekTululaCreek3 4 5 6 NCDOT - Division 14Corridor K ImprovementsSTIP Project No. A-0009C Graham County, NC Prepared by ECL on 2020-01-13Revised by ALK on 2020-03-31 Passing & Climbing Sections C:\Users\alekennedy\Desktop\A-0009 Desktop\MXDs\A-0009C_Passing_Climbing_envfeats.mxd Revised: 2020-09-16 By: alekennedyDisclaimer: This document has been prepared based on information provided by others as cited in the Notes section. Stantec has not verified the accuracy and/or completeness of this information and shall not be responsible for any errors or omissions which may be incorporated herein as a result. Stantec assumes no responsibility for data supplied in electronic format, and the recipient accepts full responsibility for verifying the accuracy and completeness of the data. LegendPassing LanesClimbing LanesHydraulic Site ï Cemetery 89:s Graham County Fire Dept î Religious Facility 4 Daycare/School Water Supply Intakes Water Tanks $#Regional Underground Storage Tanks Historic ArchitectureRecommended Eligble Recommended Eligible DistrictNRHP BoundariesPotential Jurisdictional Perennial StreamPotential Jurisdictional Intermittent StreamSelect Culverts/Pipes/BridgesPotential Jurisdictional WetlandFloodplain FloodwayGeologic Map Unit ZweTribal Land ($$¯Project Location Client/Project Figure No. Title 0 1,000 2,000Feet (At original document size of 11x17) 1:12,000 NC DEPARTMENT OF TRANSPORTATIONDIVISION OF HIGHWAYSDIVISION 14""28 ""143 £¤129 3 4 2 1 1 ¹ Left turn lane Right turn lane Left turn lane Left turn lane Left turn lane Left turn lane Left turn lane Left turn lane Left turn lane 1,684 ft 5,144 ft2,569 ft 2,601 ft $#$#$# $# $# $# $#$# î ï ï ""143Cheoah ""143 ""143 John A.Cody HouseJohn & RubyCody House Cody House Patton GwynnDenton House Randolph-StewartHouse WJ WL WQ WR WS WUWV WW PCPD WZ WAA WAB WAD WAE WAF PE WAI WAJWAJ WAK WAM WAF WAG WR SWPigpenBranch SAASZPi gpenBr anchSRSV SP SYSX STSADSACSAB SU 9 8 5 6 7 NCDOT - Division 14Corridor K ImprovementsSTIP Project No. A-0009C Graham County, NC Prepared by ECL on 2020-01-21Revised by ALK on 2020-03-31 Passing & Climbing Sections C:\Users\alekennedy\Desktop\A-0009 Desktop\MXDs\A-0009C_Passing_Climbing_envfeats_2.mxd Revised: 2020-09-16 By: alekennedyDisclaimer: This document has been prepared based on information provided by others as cited in the Notes section. Stantec has not verified the accuracy and/or completeness of this information and shall not be responsible for any errors or omissions which may be incorporated herein as a result. Stantec assumes no responsibility for data supplied in electronic format, and the recipient accepts full responsibility for verifying the accuracy and completeness of the data.($$¯Project Location Client/Project Figure No. Title 0 1,000 2,000Feet (At original document size of 11x17) 1:12,000 NC DEPARTMENT OF TRANSPORTATIONDIVISION OF HIGHWAYSDIVISION 14""28 ""143 £¤129 3 4 2 1 2 ¹ Left turn lane LegendPassing LanesClimbing LanesHydraulic Site ï Cemetery î Religious Facility Historic ArchitectureRecommended Eligble ContributingRecommended Eligible DistrictNRHP BoundariesPotential Jurisdictional Perennial StreamPotential Jurisdictional Intermittent StreamSelect Culverts/Pipes/BridgesPotential Jurisdictional WetlandFloodplain FloodwayNational Forest System LandsGame Lands 5,144 ft 2,601 ft 3,095 ft 214 ft 2,802 ft 2,133 ft $# ï ""28 ""143 ""143 Stecoah ""143 Left turn lane WAM WAN WAP WAO WAO PF WAY WBX WBV PK WBW WBZWBZ SFDSEWSCLSCI SBMSBF SFF SBHSATSAW SBRSAN S A U SBBS B L SBSSEDStillhouseBranchS E I S A ISAHSAJ SAVSEVSE T SES CodyBranch S B A OrrBranchSAJSBJ S A F S A G StillhouseBranchSBEJohnson'sGapBranchS A Y SBC C arv er B ra n c hSBISBDSAMCar v e r B ranch S A X SBKSBNSweetwa te rCreekRandolph-StewartHouse 10 2122 NCDOT - Division 14Corridor K ImprovementsSTIP Project No. A-0009C Graham County, NC Prepared by ECL on 2020-01-21Revised by ALK on 2020-03-31 Passing & Climbing Sections C:\Users\alekennedy\Desktop\A-0009 Desktop\MXDs\A-0009C_Passing_Climbing_envfeats_3.mxd Revised: 2020-09-16 By: alekennedyDisclaimer: This document has been prepared based on information provided by others as cited in the Notes section. Stantec has not verified the accuracy and/or completeness of this information and shall not be responsible for any errors or omissions which may be incorporated herein as a result. Stantec assumes no responsibility for data supplied in electronic format, and the recipient accepts full responsibility for verifying the accuracy and completeness of the data. LegendPassing LanesClimbing LanesHydraulic SiteWater Supply Intakes $#Regional Underground Storage Tanks Historic ArchitectureRecommended Eligble NRHP BoundariesAppalachian TrailPotential Jurisdictional Perennial StreamPotential Jurisdictional Intermittent StreamSelect Culverts/Pipes/BridgesPotential Jurisdictional WetlandFloodplainIndiana Bat Potential Habitat National Forest System LandsGeologic Map Unit ZweTribal LandNatural Heritage Program AreasGame Lands ($$¯Project Location Client/Project Figure No. Title 0 1,000 2,000Feet (At original document size of 11x17) 1:12,000 NC DEPARTMENT OF TRANSPORTATIONDIVISION OF HIGHWAYSDIVISION 14""28 ""143 £¤129 3 4 2 1 3 ¹ 2,133 ft 11,299 ft 10,075 ft 6,724 ft $# î î ï ï ï ï ""28 ""143 Stecoah S-2 Tunnel SW-1A Tunnel B-1A & B-1BB-2A & B-2B WBQ WBP PG PH WBU PJ PI WBM PM PL SECSEES D X SEBSDVSDZSEASDW SDUSCBSCESCG SBU S B V SC BSEFSBW SDWSBNSBZSDTSEREdwardsBranchSCFSBY WolfCreekSCCSCDStecoahCreekCarverBranch StecoahSchool StecoahBaptistChurch Boxed House 24 25 26 NCDOT - Division 14Corridor K ImprovementsSTIP Project No. A-0009C Graham County, NC Prepared by ECL on 2020-01-21Revised by ALK on 2020-03-31 Passing & Climbing Sections C:\Users\alekennedy\Desktop\A-0009 Desktop\MXDs\A-0009C_Passing_Climbing_envfeats_4.mxd Revised: 2020-09-16 By: alekennedyDisclaimer: This document has been prepared based on information provided by others as cited in the Notes section. Stantec has not verified the accuracy and/or completeness of this information and shall not be responsible for any errors or omissions which may be incorporated herein as a result. Stantec assumes no responsibility for data supplied in electronic format, and the recipient accepts full responsibility for verifying the accuracy and completeness of the data. LegendPassing LanesClimbing LanesHydraulic Site ï Cemetery Stecoah Valley Center î Religious Facility Water Supply Intakes Historic ArchitectureRecommended EligbleNRHP BoundariesPotential Jurisdictional Perennial StreamPotential Jurisdictional Intermittent StreamSelect Culverts/Pipes/BridgesPotential Jurisdictional WetlandFloodplain Indiana Bat Potential HabitatNational Forest System LandsGeologic Map Unit ZweNatural Heritage Program AreasGame Lands ($$¯Project Location Client/Project Figure No. Title 0 1,000 2,000Feet (At original document size of 11x17) 1:12,000 NC DEPARTMENT OF TRANSPORTATIONDIVISION OF HIGHWAYSDIVISION 14""28 ""143 £¤129 3 4 2 1 4 ¹ Left turn lane Left turn lane Left turn lane 1,487 ft 6,724 ft 5,162 ft 2,221 ft