item speed modifiers stack.

[Mageziya]

The real question here is: If you get two pairs of shoes, treads with shoes on, and do tons of meth; do you go so fast you gib on collision?

Gotta Speed, Keed.

What is the fastest running speed in this game?

Treads + OMJ Shoes + Multiple Different Stimms (Adrenaline Rush mutation for ease of access. Meth + Energy Drink + Epinephrine) + Other Stims (Assuming they stack, quickly checking the wiki: Triple Meth + Bath Salts + Aransep + Coffee + Syndicate Stimulants ) + This Bug (Assuming it's not yet removed.).

 What other things increased speed? I think Jetpack movespeed is based on walking speed and also adds some speed to your movement if you're in space. (Does it add more if you don't wear a space suit?) In addition, a massive combination of medical reagents to counter severe damage from space and meth. (Sulfadide, Charcoal, Salicyclic acid, Omnizine if you're lucky / raided the MD's fancy new locker.) Also I think I'm mixing up speed buffs and stamina buffs, but it seems that they're correlated.

A little part of me hopes that its possible to move so fast that Byond outright breaks.