Fundamentals of Transportation/Horizontal Curves/Additional Problems
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Additional Questions
[edit | edit source]- Name 4 types of horizontal curves.
- When are the non-simple types most used? Why are reverse curves so bad? → Special applications, including mountains, restricted right-of-way, or anywhere that a simple curve cannot be feasibly used.
- How is weather accounted for (e.g. ice) → superelevation (e)
- Explain m? When would m and M be equal? Are the equations for “m” used in determining the placement of buildings or billboards on existing roadways? → Used as a justification to keep stuff off the side of the road. May be used in roadway construction to avoid unmovable objects, or when placing objects to avoid unmovable road.
- When should you design speed for curves rather than the curve for speed? → If it is new construction, design the radius to serve the desired speed. If you are setting speed limits, set the speed based on the existing curve.
- When the angle increases, does the tangent length increase or decrease
- Write the constraints on the calculation of horizontal curves
- What are the characteristics of horizontal curves
- Draw a simple horizontal curve and its components.
- Can one add T to the PI station to get the station of the PC? (No)
- How common is a horizontal curve on a vertical curve? → Depends on where you are, very common in mountainous areas. Not especially uncommon.
- Are most horizontal curves designed using circles? → (In US, almost uniformly yes. It is also easier for driver, who just needs to set the steering wheel, constant readjustment is not required )
- In English Units what does station 10+25 mean? It indicates the station is 1025 feet from 0+00.
- On concrete roads there are grooves perpendicular to the direction of traffic to increase stopping road friction. Do these grooves (rumblestrips) reduce side friction?
- What is maximum superelevation when a road is really icy? → superelevation cannot change seasonally (it would be too expensive to jack up the road). So Max is annual.
- Why are side friction factors for urban and rural roads different? What are different factors in rural vs. urban areas?
- Why is Radius of curvature important when building roads?
- What are some of the highest values of e and around the country?
- Why do the standards (maximums/minimums) for e and change with location?
- Label all of the forces acting on a vehicle traveling up a hill (and around a corner)
- What is curve resistance? What affects is? Why does it matter?
- What are the main variables used in curvature problems, superelevation?
- Why do engineers bank curves?
- What is centrifugal force?
- Why would an engineer want to increase or decrease the radius of curvature?
- What does superelevation represent
- What shapes do horizontal and vertical curves have. Why is this helpful for the driver
- If you want to decrease , what strategies do you have?
- Is side friction the same as static friction? What does it mean?
- When the max value of is given, can a smaller number be used in the final answer → yes
- What is superelevation? How is it affected by centrifugal force?
- How does affect design speeds