Map travel (also referred to as travel, warp, map, switch and move), accessed by opening your World Map (M key by default), is a way to move quickly between outposts that you have unlocked, zone out of areas and switch between campaigns you have purchased.
Travel between outposts
To select an outpost to travel to, simply open up your map (M key by default) and click on it. If you are happy with district selection, click on the Travel button. If you wish to change districts, simply click on the drop-down menu and select the district you wish to go to.
A faster, alternative method is to double-click on the town you wish to travel to. This will automatically assign the district for you and send you there.
Traveling with a party
When a party leader travels from within a town or outpost, the entire party will be transported to the chosen location, assuming the destination party limit is high enough (for example, it is not possible to map travel a group of six people from Lion's Arch to Ascalon City, because the party limit in Ascalon is 4*). If any other party members are ineligible to travel to that location, the party leader will be given the option to leave them behind, still transporting the rest of the group.
Party travel is delayed by about 10 seconds, where a message is displayed to each player informing them of the location the party is about to be transported to. This prevents the party leader from continuously transporting party members without their agreement, and gives the other party members time to object. It is not possible for party members to leave during this timer unless they transport themselves to a different outpost.
If any other member of the party tries to map travel (or the leader tries to travel while in an explorable area), they will receive a message saying they must leave their party to do this. If they confirm, they will leave the party and travel to the destination alone.
Although the leader cannot transport the party while in an explorable area, it is possible for the entire party to resign by each player typing the
/resign command. The party will be killed (though this will not result in a death that is counted), and the leader is given the option of transporting the party to their last outpost. Every player must resign in order for this to work.
* It is possible for larger groups to enter outposts with lower limits by walking through the portals, rather than map-traveling. E.g. a group of 8 people can enter Lion's Arch if they run there from Temple of the Ages.