Underpass

Underpass is a large multiplayer map in Call of Duty: Modern Warfare 2.

Overview
Underpass takes place in the rain under the remains of a highway overpass. It's a great map for all types of weapons. It has narrow corners that make for unrivaled camping spots and wide curves that can hold devastating firefights. Players must be careful moving around, as it is a perfect map for hiding claymores and staging ambushes. In spectator mode, one can see the rest of the highway, and a large bridge.

Gameplay
Underpass is mostly a hit and run map, although there is almost constantly a sniper at either end of the map. Silencers work great on this map, since firing without a silencer will produce bright flashes at the tip of the barrel when firing, which will be heavily contrasted in the darkness of this map.

Controlling Killstreaks
Many air based killstreaks are little more than useless on this map, due to the tight and in-door nature of the map. Another downfall of killstreaks on this map is that Care Packages, Emergency Airdrops or Sentry Guns can get stuck on the overpass overhead quite easily. One of the safest places to call in Care Packages, Emergency Airdrops or Sentry Guns is in the parking lot on the far edge of the map, as people rarely venture over there.

The player should be aware of pinpoint airstrikes, it is easy to call them in on the highway rendering them totally useless.

Sniping
The Thermal Scope is highly effective on this map as it is very dark and player's images stand out as bright-white. Correspondingly, Cold Blooded is very effective at hiding from Thermal Scope users.

Warehouse B is a popular sniper ambush point, as a player can climb onto the short roof and go prone, as well as putting another member in the tall grass, giving them an easy opportunity to shred anyone coming up the side.

The small, red bricked, two story shack is popular for snipers and is perfect for getting one or two quick kills. It's open on all sides, but there's only one path up, so a sniper with a claymore could easily camp out there for an extended period.

It is almost impossible to spot a sniper who is hiding in the underbrush, especially if the player has Cold-Blooded, and has a camouflaged sniper rifle with a small sidearm or dark weapon. This map is great for playing dead in a Ghillie suit, because of the difficulty of identifying targets who are not moving at all.

Camping
The grass on this level is so tall, ambushing an enemy is fairly easy; even more so when Cold-Blooded and/or Ninja is used, claymores are also very useful in the long grass as one cannot see the red trip lines. Heartbeat Sensors can be used to great effect in the in-door sections of the map.

It's possible to get on top of the large cluster of buildings in the center of the map. The player can get on the roof from climbing a pile of boxes, leaping from the burnt-out car, using the ladder within the shacks, or by jumping off the concrete piling with the ladder. Another camping spot is on a catwalk in the large warehouse with the tanks and long stairwell. Climb the tank from the upper floor and then climb onto the high beams. This is a popular spot for ambushing. The dark corner next to the stairs is a potential location to use controllable killstreaks or ambushes.

Stealth
Stealth can be a major factor on this map. Using a silenced weapon with a Heartbeat Sensor can greatly help a player stay safe and not show up on UAV radar. Ghillie Suits also can help a player blend in when they are in the tall grass.

Trivia

 * In a small building in the middle of the map, there is a blue poster on the wall with the word "Roycewicz" and a phone number. Roycewicz was the private the player saved in Call of Duty 4: Modern Warfare in the mission "The Bog", and is a lead member of the Infinity Ward map design team.


 * There is a small train depot in this map with train cars similar to the ones in the map Derail, they also say Kriegler on them. This shows that Underpass was likely to have been one of the maps to have the Train run through.
 * There is a poster up on many walls advertising a Infinity Ward "Rock Fest" underneath an African-American man with the name "Griggs", and has the Infinity Ward symbol on the top-right corner. This is a possible reference to Staff Sergeant Griggs from Call of Duty 4. Griggs is also the name of an Infinity Ward member.
 * There is a teddy bear in a warehouse on the catwalk.
 * There is a wall on the map that has "INFIDEL" written on it. On this wall there are also painted pictures of the AK-47 and Al-Asad.
 * There is a small banana plant on this map which can't be shot through, even with FMJ equipped, similar to the ones in Favela.
 * Some of the shipping containers have IWCOD written on their doors, no doubt a reference to the Call of Duty franchise.
 * On the wooden walk on the bridge there is a take out box that has a smiley face and a message that says, "Have a nice day." This is a reference to one of the "Police Academy" movies. The villain shoots a smiley face and Tackleberry shoots the phrase "Have a nice day." This is also seen in Forrest Gump.
 * There is a mattress on the ground near the sniping spot at Flag A on the side with no ramp, and you can jump from the higher floor onto it and not get damaged, much like the mattresses in Afghan.
 * The ladder to the lookout tower is very long and if climbing, the player can become extremely vulnerable to fire.