  For two points $p$ and $q$ in the plane, a straight line $h$, called a
highway, and a real $v>1$, we define the \emph{travel time} (also known as the
\emph{city distance}) from $p$ and $q$ to be the time needed to traverse a
quickest path from $p$ to $q$, where the distance is measured with speed $v$ on
$h$ and with speed 1 in the underlying metric elsewhere.
  Given a set $S$ of $n$ points in the plane and a highway speed $v$, we
consider the problem of finding a \emph{highway} that minimizes the maximum
travel time over all pairs of points in $S$. If the orientation of the highway
is fixed, the optimal highway can be computed in linear time, both for the
$L_1$- and the Euclidean metric as the underlying metric. If arbitrary
orientations are allowed, then the optimal highway can be computed in $O(n^{2}
\log n)$ time. We also consider the problem of computing an optimal pair of
highways, one being horizontal, one vertical.
