3.28 Circular city, revisited again Suppose we modify the previous example so that travel from the outer point to the inner point, when it reaches the inner circle (say of radius R₂ if R₂ < R₁), proceeds from that point either along an arc of radius R₂ (as in Problem 3.27) or through the city center along two radial routes directly to the possiblities are shown in Figure P3.28.