Like Route 18 at the southern end of Cycling RoadRBYGSCFRLGHGSS/Pokémon Road,PE Route 16 runs directly east-west for its entire length.
Five paces outside Celadon, a cuttable tree blocks a passage leading to the north half of Route 16. Trainers with a Pokémon that can use CutRBYGSCFRLGHGSS or the Secret Technique Chop DownPE can get past the tree. Several paces west of this spot, Route 16 narrows before widening just east of a gate. Before Generation VII, Trainers are forced to board their Bicycle or, in the event that they do not own a Bicycle, are forced to return east to Celadon. In Generation VII, Trainers can pass through at any point after waking Snorlax, as Cycling Road has reopened as Pokémon Road.
Now on the bike path, the remainder of the route is filled with Bikers possessing mostly Poison-type Pokémon before Generation VII. Near the middle of the group, Route 16 turns south for a short distance before becoming Route 17 north of Route 17's grassy area.
A sleeping Snorlax is found at the point where Route 16 becomes narrow in Generation I and III. In Generation VII, it is found before the cuttable tree. To move it, Trainers must play a Poké Flute to awaken the Pokémon.
The northern half of the route proceeds directly north of the cuttable tree before turning west at the lone patch of grass on Route 16. In Generation III only, just west of this patch are a pair of Trainers. Five paces west of the grass is the north half of the gate.
On the other side of the station, which does not require Trainers to ride a bike in this area in any Generation, the only item of interest before Generation VII is a house, used as a secret resort, owned by a reclusive Trainer. In exchange for keeping her whereabouts a secret, she will give Trainers HM02 (Fly)RBYFRLG or TM14 (Fly).PE A pair of men are found here in Generation IV; the elder of the two will teach the player a trendy phrase. In Generation VII, the outside of this area also has two Punk Guys and a Roughneck.
The route terminates in a dead end just west of the house.
Only few minor changes are visible between these generations. In Generation III, trees are added above the north road and the gates are closer to each other. Also, the east sign is moved to the center fence.
The route was shortened by half in Generation II. Also, every Trainer was removed from the route and the gate on the northern path was eliminated. The recluse Trainer is no longer present and may have moved to Route 28. The sign is also moved to the north fence.
The amount of grass was also reduced.
In Generation IV, the route increased in length slightly and due to this had its layout tweaked. The route starts out as a straight path exiting Celadon City and then turning south and going down a longer path with the cut-able tree from all previous generations leading to the side path on the left side of the end of the main path. The path then turns west again and up two sets of stairs into the gate. Like Generation II, there are no Trainers to be found and the gate on the northern path was eliminated. Some hills with trees are added to the route as well to create a 3D approach.
Route 16 first appeared in Tauros the Tyrant, where Team Rocket attacked Green there, trying to get back a floppy disk she had stolen from them, which contained vital information about Mew, required to track down the elusive Pokémon. In the end, Green managed to trick Team Rocket by having her Dittytransform into a copy of Team Rocket's Tauros and having it then command Team Rocket's other Pokémon to attack their Trainers, making her getaway in the confusion.
The route appeared again in The Jynx Jinx. After Green and Red had managed to track down Mew with Green's Silph Scope, Team Rocket showed up in order to catch Mew for themselves. However, thanks to Red distracting Team Rocket with Poli, Mew was able to counterattack and knock out the evil team members and their Jynx before escaping. This didn't bother Green, however, as she had managed to catch a valuable photo of Mew during the incident.
The route appeared once more in A Tale of Ninetales. While leaving Celadon City, Red bumped into Blue, who was chasing his recently obtained and still untamed Porygon, causing both Trainers to drop their Poké Balls. Later, when Red tried to save two women from a group of rampaging wild Pokémon, he found out that his Pokémon had been swapped out with Blue's during the earlier confusion. During the time Red spent with Blue's Pokémon, he only managed to catch two new Pokémon: a Krabby and a Diglett. He later re-encountered Blue when he was trying to catch a wild Ninetales with Pika. When Red sent out Blue's Machoke to defend himself from Ninetales's attacks, the Superpower Pokémon suddenly evolved into a Machamp, subduing the Fox Pokémon. Both Red and Blue threw their Poké Balls simultaneously at the wild Fire-type, and although Red's Ball hit it first, Blue claimed it for himself under the excuse that his Pokémon had been the one weakening it. Afterwards, Red and Blue returned their own Pokémon to each other.