Complex sentence: The CBBT was in default of its toll revenue bonds for several years shortly after its completion, but these were repaid as traffic volume increased, and additional bridges were constructed to reduce the likelihood of future disruption of revenue due to accidents.
Split into simpler sentences: The CBBT was in default of its toll revenue bonds for several years shortly after its completion, but these were repaid as traffic volume increased. Additional bridges were constructed later to reduce the likelihood of future disruption of revenue due to accidents.