The 37-year-old, most recently player-manager of non-league side Egerton, died on Tuesday.
Samuel made 199 appearances for Villa after signing with the club in 1998, and played 83 times for Bolton between 2007 and 2011.
The Trinidad and Tobago Football Association said he had "collided with an oncoming vehicle".
"We are deeply saddened to hear of the death of our former player Jlloyd Samuel at the age of just 37 in a car accident," Championship side Villa said on Twitter.
"Our players will wear black armbands as a mark of respect tonight [in their play-off semi-final] and our thoughts are with his friends and family at this very difficult time."
Samuel won two international caps for Trinidad and Tobago, and also played club football in Iran between 2011 and 2015.