Question

Problem 01 (Similar to Book Problem 3-12) A horizontal curve has the following features: Existing horizontal curve radius: Existing superelevation: Posted speed limit: 900 ft 0.06 ft/ft 60 mph Given the noted existing features, answer the following: a) Is this a hazardous location? If so, why? (Answer: Yup, because the car will "fly" out of the curve.) Provide calculations to support your answer b) Noting that this is a hazardous curve, one option to address the situation is to change the horizontal curvature of the road. What is an appropriate radius for a new curve, given that we want the speed limit and banking of the roadway to remain as-is? Resource for Problem 01 U.S. CUSTOMARY 0.50 0.45 0.40 0.35 0.30 Assumed for low-speed design 0.25 0.20 0.15 0.10 Assumed for high-speed design 0.05 30 40 10 20 50 70 80 Speed (mph) Source: AASHTO (2018, p. 3-27, Figure 3-4 Side Friction Factors Assumed for Design) Side Friction Factor (

Answer 1

Answer: o F.B.D : mv R . tao y=b. Ing. tano = e = 0.06 ft/Ft. Efyzo 2 N = Mg sin (90-0) + mv sine. N = Mg Case mu sino N = mg cose + mv sine > {fx=0. R mv R Coso ng Cos (90-0) TYN. my coso = mg sino +b (img cos 0 + mu sino) mv (coso-bsino) = ng sinothing cose. y coso (1-b tano) = mg coso (tano +b) bre R9 be eccl, bel so beccel. bte - R b+0.006 (1.467860² 900x32.2 [6= 0.207 yes because Yes because rrection for frection equal to 0.125. of somph at speed

b. Peabte 0. 125 + 0.06 - (1.467 X6002 R.32.2 0-185 - (7747.529 RX 32.2 R = 1300.57 ft please rate my Ansun