Complex sentence: Ligier and Larrousse--and the Le Mans region's focus on its 24-hour race, whilst changes to the sport's technical regulations as a result of the deaths of Roland Ratzenberger and Ayrton Senna at the 1994 San Marino Grand Prix further hindered progress.
Split into simpler sentences: Ligier and Larrousse--and the Le Mans region's focus on its 24-hour race. In addition, changes to the sport's technical regulations as a result of the deaths of Roland Ratzenberger and Ayrton Senna at the 1994 San Marino Grand Prix further hindered progress.