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Page 1 i <br /> t 1fli`, %''t j I.l,• {�!i i t <br /> `eR' n ki)UTA LOCATION AND I)ES11'N lSf.fslff?h7'ti f)f 111ti t•t? 5t l: �'t t <br /> { Design speed,mph <br /> It .iv 'f I.!. <br /> t 2540 34 d0 54 647 70 ° g{I {E ' <br /> jf/5: .lti.. '.} i : <br /> 20D0 <br /> i Total dt+dZ+d3+d{ <br /> zl f540 R j" i It -A1E <br /> 1040 <br /> i c 544 da Fre.07., ttht <br /> i 4 � �3_ c. -_ A loom exact value of Ai'n hl <br /> 34 d4 ; 54 64 < <br /> I t S ( {}} <br /> [ Average speed of passing vehicle,mph cos <br /> no.OIL Tothl pasaltia eight diatanco for twa-lanc highwaYs. <br /> we have M <br /> ml <br /> t Tito nominal eight distance is not the chord AB; it is the arc -• i i.;e ;'' '- ° ;t <br /> Oil ended by this chord representing the actual path traversed by in which Q � {vf�43 X f). �,`. <br /> t',.ii' S ? ? r1 trintl'ihul eair- i <br /> the car, Since this its the stepping distance that can be utilized. Tl►a clearnnrta a tik{trup . ilia I f `d <br /> 9'lte radius of bide path in about Q ft shorter than the center-line Bzsmple i. -"'•`' +,'i it I' ut' n its,t4�tt?iCFy 1W- <br /> -line ? AMe egtht(lj9taE1CC tYltCR+tuutttl e;�' <br /> i <br /> radius iraCll to ilia formulas which follow. I)eductions of 6 ft from ti'CCi;ilia n,tnin>ifnt rtuhtre'tit, is <br /> 40 i+ <br /> i the calculated values of M may be made for greater accuracy. 8alulien. Using E. (lime}-, , st {�( j j ; ► ; : E ,' : <br /> liotvever. Clio assumption made below that chard AC� JS tends � � ': � �' � x ,�it <br /> t (1{)f l Q <br /> i to compensate for this difference. <br /> .3 <L. <br /> From Pig.U7, <br /> ! i a'it <br /> Case 1. a�- { <br /> Example 9. -tiivcn I) �4.°.#� i{ � t >i}� ? WI.I= 1 <br /> AC*= AA= - Ms n} case to xrt obstruction. <br /> (; @i, . <br /> and 1171a R' (R — M)*, (i{) 3otufiau. (u} F7aing Eq. tte,3 # I 'g 4:1 "_ <br /> i Suhstituting(b)in(Q), letting AC 1$, and reducing, the got (6) Uning Ell.(169).U > i, 3 t!+' <br /> # Fig. i It cl .{•I dry+rint€t tile {. <br /> s Sa Caae x. b> L. In g t ttnits•t:l <br /> r d t• ey tt; (.l1C.l <br /> R 8A9 (lGG) curve on ttr the tangents a It + <br /> L F d - <br /> d' ' _i#) �`, }f It tlsb <br /> Ifi curvature, so that S.= ii <br /> 4 and S' — 8R X At ( 7) triangles ACD,ADO,and A��I�. <br /> tj <br /> �' 71:•f'' .i t �J Vii{ tl!t i <br />