The Texas Transportation Institute (TTI) in the US has unveiled a study, which has an updated list of Texas’s 100 most congested roadways.

IH 45 in Harris country received the first place among congested roadways with an annual delay of 4,507,059 hours, which cost the state $98.03m.

The study has used a new report methodology, by combining the Texas Department of Transportation roadway inventory data and traffic volume data with the INRIX statewide historical speed data.

The integration is expected to offer a more accurate and detailed view of traffic conditions than the estimated traffic speeds used last year.

The study is a state legislative mandate established in 2009 to identify, quantify and share with the public the most congested locations in the Texas.

The report also highlights the efforts underway by TxDOT to improve key chokepoints in the state.

INRIX is a provider of traffic information and driver services in the US.