I'm sorry to hear if the tragedy.
But KD is right and I'll go further and outright say this has nothing to do with traffic.
According to what little we get from the report he was speeding, without a helmet, and hit the back of a truck. Three strikes that were all easily avoidable and any one might have made a difference.
If the area is full of traffic that just makes each of those poor choices even worse.
I say this having ridden plenty in some of the worst traffic in this nation including: NYC, Philly, DC, as well as occasions in LA and Atlanta. You don't have to ride like a maniac around traffic, you can stay in the slow lanes and slow everything down that happens around you. Hell, if the traffic is that bad you're probably already at much more manageable (slow) speeds in the first place.