fast, quick, short
The shortest route home is along the shore.

convenient, easy
best
long
direct
circuitous, circular, indirect, roundabout, tortuous (esp. BrE)
a circuitous route through the narrow side streets

dangerous, safe
attractive, beautiful (esp. BrE), scenic
We had plenty of time so we took the scenic route.

accessible
alternate (AmE), alternative, different
The snow forced us to take an alternative route.

main, major, trunk (esp. BrE)
air, overland, sea
bus, cycle (BrE)
shipping, supply, trade
coastal
east-west, southerly, southern, etc.
transatlantic (esp. BrE), transcontinental (esp. AmE), etc.
tourist
migration
well-travelled/well-traveled
traditional
access
escape
parade

follow, go, take, use
choose, find, map out, plan, work out
You'll have to plan your route carefully.

try
know
The bus driver did not seem to know the route.

trace
retrace
We retraced our route in an attempt to get back on the right path.

fly, travel
The airline currently flies this route twice a day.

cross sth, follow sth, go, pass through sth, run, take sb
The alternative route takes you along the river.

turn (esp. BrE)
lead
lie
Our route lay straight ahead and downhill.

connect sth, link sth
the trade routes linking Persia and China

map

along the route
There are plenty of hotels along the route.

on the route
We live on the school bus route.

route between
the most direct route between Bangkok and Chiang Mai

route from
the air route from Berlin to Beijing

route through
a scenic route through the south of France

route to
the shortest route to Manila
the best route to success

en route (= on the way)
We'll stop for lunch en route.

Route is used with these nouns as the object:
traffic