How far can I travel before Pokemon Go thinks I'm teleporting?

The most in-depth answer I was able to find regarding this is here. It seems like you will be soft-banned (which is temporary and wears off relatively quickly, despite the harshness of the term) if the GPS pings you in two distant points without a reasonable amount of time to travel between them.

Cars:

• Driving at 45 mph for 1 hour earned no ban
• Driving at 65 mph for 1 hour earned no ban

I can’t speak for higher speeds, but a consistent speed of up to 65 for an hour was tested and no bans were earned. Even though I was not banned, be wary!

GPS Spoofing: This data was acquired using a dummy account

• ~500 ft. No Ban
• ~1000 ft. No Ban
• ~2000 ft. No Ban
• ~1 Mi. First inconsistent ban (Didn’t earn a ban everytime) Lasted between 5 and 10 minutes.
• ~2 Mi. First consistent bans (Earned everytime) Lasted between 5 and 30 minutes.
• ~5 Mi.+ Ban Earned This ban duration seems more inconsistent. Traveling 10 Mi. earned me a 20 min. ban and a jump of ~800 Mi. only earned me ~15 min. ban.

From personal experience, I drive roughly 26 miles to work, about 5-7 miles residential and the rest on the freeway. Having the game run while driving through the residential area (speed limit ~30-40 mph) has never resulted in any sort of soft ban for me. Bear in mind, I lock my phone when driving on the highway, since there is little to no chance of me encountering anything.

No, the game will not think you're cheating if you do this. It's not about distance travelled while the game is off, but how fast you travel.

I regularly grab the stop by my house and then drive to work and grab the stops there, and have never had an issue. (My work is about the same distance away from home as yours is.) I also drive from spot to spot, or play while someone else is driving, and it's often for much longer distances than you're talking about. I've never been soft banned or otherwise experienced any issues. Many, many people play this way, and I've never heard of a ban for driving from place to place, regardless of the distance.

This may not be the "concrete evidence" you are looking for, but think about it logically. Obviously people are going to drive around, and obviously they will take advantage of being in different places to catch new Pokemon. That's the entire point of the game.

I don't think anyone knows what the exact speed cut off is, but you aren't going to hit it in a car.

I've gone from LA to SF with an hour of no Pokemon Go in between. Basically, simulated flight time. If I wanted to go to East Coast, I would wait 5 hours between I return to the game.

the speed cut off is about 30kmh (i live in new zealand) inn saying that this speed is while you are using the game as for the distance you can travel by what i have experienced its all do do with how you are traveling it say you were going 100km it was measure the speed by how fast a car would do it in i travel overseas alot and have never had a problem when getting off the plane and having a jam on the game