During morning rush hour, light in Mass Ave SB turns red at Wisconsin before it turns red at Cathedral. As a result, the stretch of Mass Ave between Cathedral and Wisconsin fills with cars, which prevents right turns from Cathedral EB to Mass Ave, resulting in large backups on Cathedral EB.

Comments update: 14-00277408-Traffic Signal Maintenance
3751-3799 Cathedral Avenue Northwest, Washington, DC 20016, USA
Not enough information for DDOT to respond