Incidents & accidents cause a backup of traffic and severe congestion situations. Although temporary, unexpected congestion periods can last for hours at a time.
Useful information in understanding and mitigating incident & accident related congestion may include: live traffic incident reports and alerts, traffic flow data (speeds, vehicle counts, journey times) or even status updates from social media feeds.
Such information is useful to local transport authorities who can use it to timely dispatch accident cleanup crews, control signal timings, send real-time updates to traffic message boards, or share that information with the community. All of these techniques, individually or together, are effective ways to deal with congestion.