To preface: Don't (yet) have my PC, but, I hope to build one by the fall. I've started tracking mods on Nexus in anticipation, and one of the key mods I'm looking for is a Dragon mod that works akin to When Vampires Attack....

Is there a mod out there to make people flee in the event of a dragon attack?

Well search for When Vampires attack click on the authors name and look at the other mods he has made

Or just search for Run for your lives.Or click this http://www.nexusmods.com/skyrim/mods/23906/?.You should also use the Unofficial Patches.

You rock my world. (USLEEP was the first thing I searched for.)

Kane... good luck with the PC...

http://www.nexusmods.com/skyrim/mods/3829/? it is not intuitive, but their is a toggle in the MCM menu ( meaning you need SKyUI ) that allow's you to toggle NPC and follower's into being immortal, if that doesn't suit ( for me it depends on the RP ) you can toggle "no dragon attacks in walled cities"...meaning Riverwood and the like are not "safe".... so you still need "Run for your Lives"... but it's worth it... even if only for the menu...toggles and extra dragon types... I play at "vanilla" difficulty through the mod. That...trust me.. is hard enough, but I'm sure you have read that others up the difficulty ... I like challenge... not mod induced suicide.

I did hover my mouse over that one....but I don't think I'm ready for it. Only starting out with minor tweaks and additions. Craftable clothes, sliver weapons, things like that.

When Vampires Attack AND Run for Your Lives are essential to me, and permanent in my load order. I also use UFO (even though some say it's too old) to make sure my followers are essential. I don't like the good npcs dying, especially shopkeepers, whether or not they have replacements that will take over.

Oh yes... other than DiD competition, neither one comes out of my load order. AFT can make followers essential, but does nothing for the other NPC's.. Which is why I mentioned that Deadly Dragon's has that option. Plus the extra dragon types are cool... it's just makes the dragon's deadly even at default settings, which is fine, makes them more dangerous.. and I set the timer so that they are not spawning as often as wolves.