A. If the area you are interested in is just off the map, try dragging the map with your mouse. If you are in a different city, choose your city from the Change Cities menu at the top of the page.
A. You have two options when bookmarking the map. Please choose the one that best meets your needs.
A. We are currently dependent on the local Departments of Transportation (e.g., Caltrans) for camera images. The site currently shows all the cameras we have access to. As more cameras become available, we will add them to the site.
A. To receive alerts on your cell phone, your phone and service plan need to support text messaging. While nearly all cell phones sold in the last few years support text messaging, this is sometimes an additional option you need to sign up for from your wireless service provider (e.g., AT&T Wireless, Verizon Wireless, Sprint PCS). To find out if your phone supports text messaging, just ask your wireless service provider if your phone has an email address. If it does, then it will work with Sigalert.com. If it doesn't, ask them how you can get an email address for your phone.
A. The official definition of a Sigalert is "any unplanned event that causes the closing of one lane of traffic for 30 minutes or more."
A. Sigalerts are named after an early radio engineer in Los Angeles, Loyd Sigmon. You can read more about Loyd Sigmon and the history of Sigalerts on Wikipedia.
A. You can cancel automatic renewal on your account at any time using the Billing tab of the My Account page.
You can also delete your account from the Account tab on the My Account page.
A. The traffic information comes from many different sources. In California, freeway speeds are primarily collected by Caltrans from sensors embedded in the roads. We download the raw speed data from them and display it on our site in a (hopefully) easy to use format.
Los Angeles speed data comes courtesy of the Regional Integration of Intelligent Transportation Systems (RIITS) which is sponsored the Los Angeles County Metropolitan Transportation Authority (Metro).
Many of the San Francisco Bay Area sensors come from our partner SpeedInfo.
For the outlying areas of California and rest of the country, the speed information comes from AirSage
A. No, we only have information about accidents currently affecting traffic. When an incident is removed from their logs, it is removed from our Web site as well.
A. Sigalert.com was founded by Joel Johnstone and Jonathan Berke in 1998. In 2011, Sigalert.com was sold to Clear Channel Media and Entertainment.