The URL can be used to link to this page

Home My WebLink AboutWetherholt - Balboa Turning RadiusRoadway Design Manual: Minimum Designs for Truck and Bus Turns SINGLE UNIT (SU) TRUCK DESIGN VEHICLE TURNING RADIUS ` 42 ft 112.80 ml SCALE *1:20 11:2001 / ! I --Y -- I ♦ / r ! X4].263% 1 1 i 4 1 1 r h 1 1 4 1 1 \h h\ 1 1 + h 1 1 h 4 1 1 1 Y 44 1 1 h t 1 1 hr % 1 1 r 1 1 � 1 I 1 1 1 Turning Template for Single Unit Trucks or Buses Figure 7 -1. Turning Template for Single Unit Trucks or Buses, (not to scale). NOTE: To view Figure 7 -1 to scale, click here to down load the PDF. Page 2 of 12 http: / /onlinemanuals .txdot.gov /txdotmanuals /rdw/ minimum_ designs_ truck_bus_tums.htm 2/2/2010 Roadway Design Manual: Minimum Designs for Truck and Bus Turns F x I wB -40 CWB -121 DESIGN VEHICLE RADIUS • 40 ft 112,20 m) SCALE ■1:20 11;2001 x ! x xY3 � 411 • w x x •♦ • e 00 90 s A F ✓ \ �♦ S ♦ I 1 t ♦ 1 ♦ 1 1 s 1 5 ♦I / I 11 1 ♦♦ \ l J \ \ I / I I ♦ 1 1 1 \ 1 1 I 1 \ 1 1 \ S 1 1 l / 1 I 1 l 1 1 � 1 1 1 1 1 Turning T+T010to for Semi -Trol nw with 40 ft 112.20 ml wr*8 11>06R Figure 7 -2. Turning Template for Semi - Trailer with 40 ft [12.20 m] Wheelbase, (not to scale). NOTE: To view Figure 7 -2 to scale, click here to down load the PDF. Page 3 of 12 http: / /onlinemanuals .txdot.gov /txdotmanuals /rdw/ minimum_ designs_ truck_bus_tums.htm 2/2/2010 Roadway Design Manual: Minimum Designs for Truck and Bus Turns WB -50 IWB -151 DESIGN VEHICLE RADIUS ■ 45 ft [13.72 m] SCALE ■1220 E122001 r I � ♦ J 1r �g i� I ♦ } ! l♦ y` 1\ � �.T f} f7r 7yy � �� t ft T13��1 � I !■ k--4 RAOr 45. r 4 ! ' I ! ! i r I r 1 li r r I ! 1 r I I t ! 1 I r r r ! I I ■ `T'Cd t I ! I I ! I I ' � � I 1 1 %orning TerMlote far Semi- Trailer with So ft (15.24 m] Wheelt)ase Figure 7 -3. Turning Template for Semi - Trailer with 50 ft [15.24 m] Wheelbase, (not to scale). NOTE: To view Figure 7 -3 to scale click here to down load the PDF Page 4 of 12 http: / /onlinemanuals .txdot.gov /txdotmanuals /rdw/ minimum_ designs_truck_bus_tums.htm 2/2/2010 r Ir tl 1 — 1 N so- M1 tATU k--4 RAOr 45. r 4 ! ' I ! ! i r I r 1 li r r I ! 1 r I I t ! 1 I r r r ! I I ■ `T'Cd t I ! I I ! I I ' � � I 1 1 %orning TerMlote far Semi- Trailer with So ft (15.24 m] Wheelt)ase Figure 7 -3. Turning Template for Semi - Trailer with 50 ft [15.24 m] Wheelbase, (not to scale). NOTE: To view Figure 7 -3 to scale click here to down load the PDF Page 4 of 12 http: / /onlinemanuals .txdot.gov /txdotmanuals /rdw/ minimum_ designs_truck_bus_tums.htm 2/2/2010 Roadway Design Manual: Minimum Designs for Truck and Bus Turns wB -62 CWB -191 DESIGN VEHICLE RADIUS - 45 ft 113.72 rn7 SCALE ■1:20 11:2001 p A + l . 47 ! a I/ I •` p' A I. - y_- -------------- ,. _. /s` 90 J � • �y + I ! r l rA rtry� '!'v fr` 14.t4T 1 r � D 6 ° f of f2.43 YIN IA ° ♦ ° { ° 1 �' Li t 1 ♦ 3 1 1 J \111`AajV'}�.I` 1 I ' 5 � 1 � 1 I Turning TeMlote for SwT- TroTler with 62 ft I10.9 ml Wheelbase iNaaius•45 ft 113.72 mll Figure 7 -4. Turning Template for Semi- Trailer with 62 ft [18.9 m] Wheelbase, (not to scale). NOTE: To view Figure 7 -4 to scale, click here to down load the PDF. Page 5 of 12 http: / /onlinemanuals .txdot.gov /txdotmanuals /rdw/ minimum_ designs_ truck_bus_tums.htm 2/2/2010 Roadway Design Manual: Minimum Designs for Truck and Bus Turns Page 6 of 12 Figure 7 -5. Turning Template for Semi - Trailer with 62 ft [18.9 m] Wheelbase (Radius = 75 ft [22.9 m], (not to scale). . NOTE: To view Figure 7 -5 to scale, click here to down load the PDF http: / /onlinemanuals .txdot.gov /txdotmanuals /rdw/ minimum_ designs_truck_bus_tums.htm 2/2/2010 1 % ■ Ir r r r - .. r . � r. _ _ _ - -- r r *nM 1 r r ,�� r ' I, rr g - rJr r r i IIr1 I 1 1 1 /i rrrr 1 r II 1 r♦ r r ► 1 fs 1 /r 1 VI 1 +II I / r I 4! J 1 ^ r l 1 rr y r +� -• E 2 r 1 r/ r+ ®, 0 I 7 I 1 1 i Ir } I, UP 111 II1 t 4 \Y 1 s C3 M Ln 1•J t 1 ♦ 1 1 1 (i1 J } r C) LA M d A \ v ID Ir It % ■. \ ' �� +\ ■ ■■ ■■ 66.5 ft (24.967 ■ ■�+ .�.� 62 ft 119.41 ■■ ~`� 99 ft 119.63' r � 1 ■ 4 y ' Turning iwVlole for San[- TroTler with 62 ft (10.9 ml ■hplIW" IRae[ua•75 ft [22.9 te)) Page 6 of 12 Figure 7 -5. Turning Template for Semi - Trailer with 62 ft [18.9 m] Wheelbase (Radius = 75 ft [22.9 m], (not to scale). . NOTE: To view Figure 7 -5 to scale, click here to down load the PDF http: / /onlinemanuals .txdot.gov /txdotmanuals /rdw/ minimum_ designs_truck_bus_tums.htm 2/2/2010 Roadway Design Manual: Minimum Designs for Truck and Bus Turns WB -67D IwB -20D] DESIGN VEHICLE RADIUS w 45 ft 113.72 ml SCALE ■1:20 11:2001 ♦ V 1 I 6 sir ' —�- Nr 1 ♦r �� r f�� Gg +y�45.5 TY ttt3.6 �� I Y\M1 + !. `5 ♦ � YY 11 1 t 1 1 t M1I \ I t IM1 Yt m 1 4 I M1 M1 i 1 Y y I \ 1 1 tM1 \ 1 1 S ! M1Y 1 1 1 t 1 1 OD 1 i 1 1 1 . 17 I 1 Turning Templore for OoLible -Tral W Cominatlon witm 67 ft 120.41 m1 wheelbme Page 7 of 12 Figure 7 -6. Turning Template for Double- Trailer Combination with 67 ft [20.41 m] Wheelbase, (figure not to scale). NOTE: To view Figure 7 -6 to scale, click here to down load the PDF. http: / /onlinemanuals .txdot.gov /txdotmanuals /rdw/ minimum_ designs_ truck_bus_tums.htm 2/2/2010 Roadway Design Manual: Minimum Designs for Truck and Bus Turns Figure 7 -7. (US). Example of Pavement Edge Geometry (US Customary). Page 8 of 12 http: / /onlinemanuals .txdot.gov /txdotmanuals /rdw/ minimum_ designs_ truck_bus_turns.htm 2/2/2010 EXAMPLE PAVEMENT EDGE GEOMETRY *B -50, 90 DEGREE TURN ah� a ft Q A Tf i 7:75 R -60 ft CFFSE -•9 f- 1:15 -BPEP -1115 (A) SIMPLE CURVE RADIUS WITH TAPER 0 eft 9 }t O S PG IBO tt R q1 =Ipp ft Re- p f- OFFSET -6 TV (B), 3- CENTERED SYMMETRIC COMPOUND CURVE hI 10 tt a ash b a � PC r Rp -IW Ft Rx -a0 ff R2-2W fl OFFS T,-2 £f OFFSETS -1P ft (C) 3- CENTERED ASYMMETRIC COMPOUND CURVE ExamDle of Pavement Edge Geometry (US Customary) Figure 7 -7. (US). Example of Pavement Edge Geometry (US Customary). Page 8 of 12 http: / /onlinemanuals .txdot.gov /txdotmanuals /rdw/ minimum_ designs_ truck_bus_turns.htm 2/2/2010 Roadway Design Manual: Minimum Designs for Truck and Bus Turns Figure 7 -8. (M). Example of Pavement Edge Geometry (Metric). Channelization Page 9 of 12 http: / /onliiietnanuals.txdot.gov /txdotmanuals /rdw /minimum_ designs_ truck bus _ tw -ns.htm 2/2/2010 EXAMPLE PAVEMENT EDGE GEOMETRY NB-159 90 DEGREE TURN Ica i.m �a, r 115 i R -1 M R 9 =FSET.1,d= •�1S i/ M-1:15 (A) SIMPLE CURVE RADIUS WITH TAPER E. 6n nn 5"i p� 3 Y� -55m tz -,8m CPf Y T -2. W (B) 3- CENTERED SYMMETRIC COMPOUND CURVE r PC 3Em R p, =3Bn R2-'ft H, -5M CFFSETi•1. Crli WFSET3.3.� (C) 3- CENTERED ASYMMETRIC COMPOUND CURVE Example of Pavement Edge Geometry (Metric) Figure 7 -8. (M). Example of Pavement Edge Geometry (Metric). Channelization Page 9 of 12 http: / /onliiietnanuals.txdot.gov /txdotmanuals /rdw /minimum_ designs_ truck bus _ tw -ns.htm 2/2/2010 Roadway Design Manual: Minimum Designs for Truck and Bus Turns Page 10 of 12 Where the inner edges of pavement for right turns at intersections are designed to accommodate semi - trailer combinations t where the design permits passenger vehicles to turn at 15 mph [20 km/h] or more (i.e., 50 ft [15 m] or more radius), the pavement area at the intersection may become excessively large for proper control of traffic. In these cases, channelizing islands should be used to more effectively control, direct, and/or divide traffic paths. Physically, islands should be at least 5 ft2 [4.5 m2 ] in urban and 75 ft2 [7.0 m2] for rural conditions (100 ft2 [9.0 m2] preferable for both) in size and may range from a painted to a curbed area. Alternatives to Simple Curvature To accommodate the longest vehicles, off - tracking characteristics in combination with the large (simple curve) radius that must be used results in a wide pavement area. In this regard, three- centered compound curves, or offset simple curves in combination with tapers, are preferred since they more closely fit the paths of vehicles. Table 7 -2 shows minimum edge of pavement designs for right turns to accommodate various design vehicles for turn angles varying from 60 to 120 degrees. (US Customary) Angle of Tarot (degrees) Design Vehicle Simple Curve Radius Simple Curve Radius with Taper 3- Centered Compound Curve, Symmetric 3- Centered Compound Curve, Asymmetric (ft) Radius (ft) Offset (ft) Taper Radii (ft) Offset (ft) Radii (ft) Offset (ft) 60 P 40 - - - - - - - - SU 60 - - - - - - - - WB -40 90 - - - - - - - - WB -50 150 120 3.0 15:1 200 -75 -200 5.5 200 -75 -275 2.0 -7.0 75 P 35 25 2.0 10:1 100 -75 -100 2.0 - - SU 55 45 2.0 10:1 120 -45 -120 2.0 - - - WB -40 - 60 2.0 15:1 120 -45 -120 5.0 120 -45 -195 10 -6.5 - WB -50 - 65 3.0 15:1 150 -50 -150 6.5 150 -50 -225 2.0 -10.0 90 P 30 20 2.5 10:1 100 -20 -100 2.5 - - - SU 50 40 2.0 10:1 120 -40 -120 2.0 - - - WB -40 - 45 4.0 10:1 120 -40 -120 5.0 120 -40 -200 2.0 -6.5 - WB -50 - 60 4.0 15:1 180 -60 -180 6.5 12040 -200 2.0 -10.0 105 P - 20 2.5 - 100 -20 -100 2.5 - - - SU - 35 3.0 - I00 -35 -100 3.0 - - - WB -40 - 40 4.0 - 100 -35 -100 5.0 100 -55 -200 2.0 -8.0 - WB -50 - 55 4.0 15:1 180 -45 -180 8.0 150 -40 -210 2.0 -10.0 120 P - 20 2.0 - 100 -20 -100 2.0 - - - SU - 30 3.0 - 100 -30 -100 3.0 - - - WB -40 - 35 5.0 - 120 -30 -120 6.0 100 -30 -180 2.0 -9.0 - WB -50 - 45 4.0 15:1 180 -40 -180 8.5 150 -35 -220 1 2.0 -12.0 1 "Angle of Turn" is the angle through which a vehicle travels in making a turn. It is measured from the extension of the tangent on which a vehicle approaches to the corresponding tangent on the intersecting road to which a vehicle turns. It is the same angle that is commonly called the delta angle http: / /onlinemanuals .txdot.gov /txdotmanuals /rdw/ minimum_ designs_truck_bus_tums.htm 2/2/2010 Roadway Design Manual: Minimum Designs for Truck and Bus Turns in surveying terminology. (Metric) Page 11 of 12 Angle of Total (degrees) Design Vehicle Simple Curve Radius Simple Curve Radius with Taper 3- Centered Compound Curve, Symmetric 3- Centered Compound Curve, Asymmetric (m) Radius (m) Offset (m) Taper Radii (m) Offset (in) Radii (m) Offset (m) 60 P 12 - - - - - - - - SU 18 - - - - - - -- - WB -12 28 - - - - - - - - WB -15 45 29 1.0 15:1 60 -23 -60 1.7 60 -23 -84 0.6 -2.0 75 P 11 8 0.6 10:1 30 -8 -30 0.6 - - - SU 17 14 0.6 10:1 36 -14 -36 0.6 - - - WB -12 - 18 0.6 15:1 36 -14 -36 1.5 36 -14 -60 0.6 -2.0 - WB -15 - 20 1.0 15:1 45 -15 -45 2.0 45 -15 -69 0.6 -3.0 90 P 9 6 0.8 10:1 30 -6 -30 0.8 - - SU 15 12 0.6 10:1 36 -12 -36 0.6 - - WB -12 - 14 1.2 10:1 36 -12 -36 1.5 36 -12 -60 0.6 -2.0 - WB -15 - 18 1.2 15:1 1 55 -18 -55 2.0 36 -12 -60 0.6 -3.0 105 P - 6 0.8 8:1 30 -6 -30 0.8 - - - SU - 11 1.0 10:1 30 -11 -30 1.0 - - - WB -12 - 12 1.2 10:1 30 -11 -30 1.5 30 -17 -60 0.6 -2.5 WB -15 - 17 1.2 15:1 55 -14 -55 2.5 45 -12 -64 0.6 -3.0 120 P - 6 0.6 10:1 30 -6 -30 0.6 - - - SU - 9 1.0 10:1 30 -9 -30 1.0 - - - WB -12 - 11 1.5 8:1 36 -9 -36 2.0 30 -9 -55 0.6 -2.7 - WB -15 - 14 1.2 15:1 55 -12 -55 2.6 45 -11 -67 0.6 -3.6 " "Angle of Turn" is the angle through which a vehicle travels in making a turn. It is measured from the extension of the tangent on which a vehicle approaches to the corresponding tangent on the intersecting road to which a vehicle turns. It is the same angle that is commonly called the delta angle in surveying terminology. Figure 7 -7 shows sample alternative (to simple curvature) edge of pavement geometry for a 90 degree turn using a WB 50 [WB -15] design vehicle. Although not shown in this figure, a radius of 80 ft [25 m] without channelizing island would be necessary to accommodate the wide, off - tracking path of a WB -50 [WB -15] without undesirable encroachment. A geometn design of this sort is undesirable, however, since there would be a confusing, wide expanse of surfaced area; furthermore, there is no convenient, effective location for traffic control devices. Urban Intersections http: / /onlinemanuals .txdot.gov /txdotmanuals /rdw/ minimum_ designs_ truck_bus_tums.htm 2/2/2010 Roadway Design Manual: Minimum Designs for Truck and Bus Turns Page 12 of 12 Comer radii at intersections on arterial streets should satisfy the requirements of the drivers using them to the extent practical and in consideration of the amount of right -of -way available, the angle of the intersection, numbers of and space for pedestrians, width and number of lanes on the intersecting streets, and amounts of speed reductions. The following summary is offered as a guide: • Radii of 15 ft [4.5 m] to 25 ft [7.5 m] are adequate for passenger vehicles. These radii may be provided at minor cross streets where there is little occasion for trucks to turn or at major intersections where there are parking lanes. Where the street has sufficient capacity to retain the curb lane as a parking lane for the foreseeable future, parking should be restricted for appropriate distances from the crossing. • Radii of 25 ft [7.5 m] or more at minor cross streets should be provided on new construction and on reconstruction where space permits. • Radii of 30 ft [9 m] or more at major cross streets should be provided where feasible so that an occasional truck can turn without too much encroachment. • Radii of 40 ft [ 12 m] or more, and preferably three- centered compound curves or simple curves with tapers to fit the paths of appropriate design vehicles, should be provided where large truck combinations and buses turn frequently. Larger radii are also desirable where speed reductions would cause problems. • Radii dimensions should be coordinated with crosswalk distances or special designs to make crosswalks safe for all pedestrians. For arterial - arterial urban intersections, turning radii of 75 ft [23 m] or more are desirable if frequent use is anticipated by the WB -62 [WB -19] design vehicle. Where other types of truck combinations are used as the design vehicle, pavement edg geometry as shown in Table 7 -2: Minimum Edge of Pavement Designs at Intersections and Figure 7 -7 permit the use of lesser radii. An operational measure that appears promising is to provide guidance in the form of edge lines to accommodat the turning paths of passenger cars, while providing sufficient paved area beyond the edge lines to accommodate the turning path of an occasional large vehicle. Rural Intersections In rural areas space is generally more available and speeds higher. These factors suggest more liberal designs for truck turning even when the frequency of long vehicles may not be as great as in urban areas. In the design of highway intersections with other (non - highway system) public roads, long vehicles are generally infrequen users. Minimally, the SU, or on some occasions the WB —40 [WB -12], design vehicle is appropriate for use unless special circumstances (location of a truck stop or terminal) influence the frequency of use by certain vehicle classes. For arterial intersections with collectors, the WB -40 [WB -12] design vehicle is generally appropriate and the WB -50 [WB- 15] should be used where specific circumstances warrant. For arterial - arterial intersections, use by the WB -62 [WB -19] design vehicle should be anticipated within project life. Two template layouts, Figure 7 -4 and Figure 7 -5, are shown with radii of 45 ft [13.7 m] and 75 ft [ 23 m] respectively. For turning roadway widths to be reasonable in width, a design radius of 75 ft [23 m] or more is required. Where circumstances at a particular rural arterial - arterial intersection precludes the use of the WB -62 [WB -19] design vehicle, the WB -50 [WB- 15] should be used. http: / /onlinemanuals .txdot.gov /txdotmanuals /rdw/ minimum_ designs_truck_bus_tums.htm 2/2/2010