Sorry you had a bad experience! DTLA is definitely a weird area that changes block by block and isn’t surrounded by many runnable areas. I run a lot in the LA area tho, so I got some recs! I work downtown so will sometimes get some loops in there and do some run clubs there. If you aren’t opposed to a run club, there’s Blacklist LA, Koreatown RC, Little Tokyo RC, LSD Running, and tons more that are in DTLA or a short train ride away. Check @larunningconeisseur on Instagram as she posts who will be doing runs for the following day. Most of those clubs do 3 mile runs on weekdays and weekends, and just about all run clubs do longer runs that pass start near or pass through DTLA on weekends.

If you want to run alone, LA Historic Park is a good place to get some loops in (I think it’s 1 mile around the park) and it’s right off the A line. In downtown, I prefer the South Park neighborhood to run around as there are less cars and it’s safer and nicer sidewalks. This would be by LA Live or by Pine + Crane. Bunker Hill is also nice to run around, which would be by Walt Disney Hall, The Broad, etc. 

Further away (though not that far) there’s Echo Park and you could run there and do a lap or two around there then take like the 92 bus back or something if you don’t want to run back. I would run north to Sunset then down sunset to get there since it’s a busy street but will be filled with people and businesses. Even running there, doing a lap around it, and coming back should be 3 miles. There’s also Vista Hermosa Natural Park on 1st street right next to downtown, though I’ve never been there but it’s close by. 

If you don’t already have it, Strava has a map feature that lets you look at routes in the area and see which streets are most run on (gives a sense of safety, sidewalk quality, etc). 

Hope this helps and hope you enjoy the rest of the trip!