How can you travel between terminals at DFW (Dallas Fort Worth International Airport)?

There are 2.5 ways, but in almost all cases you need the free Skylink train between terminals. If you're in a rush, the Skylink train is almost certainly fastest.

There is an interactive map which provides step-by-step directions between any two supported points. https://map.dfwairport.com/

Skylink train

Do not exit the secured area. Just find the nearest Skylink station and follow signs for your terminal (A-E) and gate (approx. 1-60). There are two stations per terminal (A-E) and two entrances to each station (one at each end of the linear station). They are accessed via escalator, elevator, or stairs.

The trains run in 2 directions in a complete circuit. The penalty for going the "wrong" direction would be 10-30 minute longer (guesstimate) train ride than the correct direction. https://www.youtube.com/watch?v=b19PF-zTZpk

Despite DFW statements otherwise*, the maximum estimated trip time is at least 12 minutes. "Trains arrive every 2 minutes". It would not shock me to find an estimated route of 15 minutes, with a real world worst case wait+travel time of 20+ minutes, if you arrive just after your train left and have to wait for the next one. (This ignores any unplanned downtime / breakdown.)

* "Average ride time of five minutes, Maximum ride time of nine minutes between farthest points" https://www.dfwairport.com/explore/plan/connect/

Walking/carts/etc. (secured area)

You can technically walk between most of the terminals without exiting the secured area (citation needed). However this is a long walk probably on the order of 3+ miles unless the terminals are adjacent and connected by a pedestrian bridge.

I think terminal E is for international flights and thus requires its own security checkpoint, but I can't confirm this. You can enter planned routes on the DFW map site and see if it makes a popup warning you that you will go through security.

DFW says when skylink is down for maintenance: https://www.dfwairport.com/skylinkfaqs/

1. Customers can walk between Terminals C & A, Terminals A & B, and Terminals B & D
2. For customers in Terminal E, there will be a shuttle available to transport them to Terminal D from Gate E33
3. Customers can also take the Terminal Link shuttles which are outside security and available every 20-25 minutes curbside
   For additional questions, call 972-973-3112

• Blue lines = alleged walkway
• Red X = no pedestrian connection within the secured area

This annotated map (red Xs added to signify no bridge) is extremely suspect. I think the bridges I put Xs over are for outside the secured area. Thus they are near useless for layovers. More info: https://www.lafp.com/projects/dfw-airport-terminal-cd-pedestrian-skybridge/

Walking/carts/etc. (leave the secured area)

There may be additional bridges outside the secured area but then you would have to go through TSA security again.