sigalert.com

March 12, 2005 8:10 PM

never get stuck on the 405 again? serving los angeles, san diego, san bernadino and riverside counties along with san francisco and miscellaneous cities throughout california, sigalert.com will give you up to the minute traffic information on almost any freeway in california, including average speeds, closed roads, detailed info re: traffic accidents, etc.
(if you're living in LA county, the only con is that it doesn't have information on the canyons...)
posted by mgkaelen (24 comments total)

This is a great tool. I wish there was something like this in Canada. Anyone know of similar sites that are for other regions? I know that there are traffic camera sites, I'm more interesting in the average speed.
posted by Sonic_Molson at 8:41 PM on March 12, 2005

In San Diego, we've had the San Diego Wireless Traffic Report which uses the same data. Not all the freeways have detectors on them, but the coverage is pretty good. You can also sign up for an account (free) where you can put in your commute route, and then you can call while you're actually stuck in traffic and it will give you the speeds along your commute. Pretty cool stuff.
posted by escher at 8:45 PM on March 12, 2005

There's definitely one for Portland. I can't give you the URL, but the guy who own(ed) LiveJournal was writing a program to parse the image and build up traffic stats :) SigAlert's map came in very handy when I was in L.A. Unfortunately the 101 is always slow on the Hollywood section. Yes, even right now it seems. 22mph at Vermont, ahoy!
posted by wackybrit at 8:56 PM on March 12, 2005

Wow, cool info for the so-cal folks. Does any Mefite other than myself have to commute over this big piece of crap? Don't laugh, but sometimes I travel an extra 25 miles just to circumvent this effing death trap. In this case the "SigAlerts" just don't help.
posted by snsranch at 8:59 PM on March 12, 2005

Also, you notice how there are no stats for the downtown freeways? Primarily the 110 and 10 in the downtown sections. Is this something to do with how they get these stats or the camera positioning? The main pattern is that there seem to be less cameras in places with taller/more buildings or large geographic features (notice no stats on the Cahuenga Pass on the 101 either - or in the 405 stretch from Marina Del Rey to LAX).
posted by wackybrit at 8:59 PM on March 12, 2005

Good find (I'm pleasantly surprised nobody's complained "CalFilter" yet...), but there's nothing at sigalert.com that explains the origin of the term "sigalert". (Three cheers for "Sig" Sigmon, L.A. radio legend)
posted by wendell at 9:00 PM on March 12, 2005

it looks like traffic.com has more than just the greater los angeles area. it requires free registration (i didn't register so i'm not sure of the quality of the site), but it serves
Atlanta
Baltimore Boston Chicago Dallas - Ft Worth Detroit Houston Los Angeles Minneapolis New York Orlando Philadelphia Phoenix Pittsburgh Providence Sacramento
San Diego San Francisco Seattle St Louis Tampa Washington DC
posted by mgkaelen at 9:04 PM on March 12, 2005

Twin Cities doesn't get as much detail, but we do get to see all the cameras.
posted by gimonca at 9:05 PM on March 12, 2005

Hmm. Very cool. I always thought it was short for a Signal Alert, as local the local news shows often place red, green or yellow "signals" over various freeway maps to illustrate traffic flow.
posted by snsranch at 9:07 PM on March 12, 2005

Also, you notice how there are no stats for the downtown freeways? Primarily the 110 and 10 in the downtown sections. Is this something to do with how they get these stats or the camera positioning?

wackybrit,, i don't think they get the stats from cameras. rather, i think there are sensors in the ground that can detect the speeds, etc. i don't know the downtown area like the back of my hand so i can't tell if there are exits missing. maybe since everything is so close together, caltrans just places the sensors further apart down there?
posted by mgkaelen at 9:09 PM on March 12, 2005

from chp.ca.gov, what is a sig alert?
posted by clyde at 9:23 PM on March 12, 2005

I use this daily. As for missing bits: Sometimes data is missing here or there. It'll reappear again after a while. Not sure why it does that.

For further SoCal traffic watching: this site, although it seems a bit too optimistic on speeds for my taste.
posted by tinamonster at 9:26 PM on March 12, 2005

Wow, thank you for this. I live in San Diego and am sure this will be useful. In fact, a friend is down here right now from Simi Valley and it took him FAR too long due to traffic. I wish I had seen this post yesterday.
posted by Stunt at 9:56 PM on March 12, 2005

How about Drive Time Traffic? It's where KFWB gets their information, except they usually add a few minutes of padding.
posted by calwatch at 10:00 PM on March 12, 2005

This is a good find! The FAQ on the site says this about traffic sensors:

Q. There are no speed dots for a stretch of freeway I use. Why?

A. The speeds that you see on our site come from sensors Caltrans has buried in the freeway. For freeways in less populated areas, these sensors often don't exist. For freeways in heavily traveled areas, the sensors are usually there but, for any number of reasons, Caltrans may not have speed information from them. Rest assured that as soon as Caltrans provides additional speed information to us, we will pass it along to you via our Web site.

This site has information on new monitoring systems currently being considered.

I saw a DOT report here that said traffic sensors sometimes don't get kept up because traffic has to be shut down in order to fix them, and that the sensor system often gets damaged by contractors who are doing work on the road.

About 20 years ago I had the opportunity to see a wall display of traffic sensor information at Caltrans's downtown office. The information there was just the same as what Sigalert.com has now! That's cash-starved state services for you... :-/
posted by halonine at 10:14 PM on March 12, 2005

I can vouch for the accuracy of this. Like tinamonster, I use this every day, and it is amazingly accurate and up-to-date.
posted by apocalypse miaow at 12:54 AM on March 13, 2005

Traffic.com does seems to do a fine job of keeping track of the traffic here in Pittsburgh but that information is completely useless to me. Driving in from the eastern suburbs, there is only one road that you can take, 376, and it is always stop and go during rush hour. So my choices are take 60 to 90 minutes to drive the eighteen miles to work or call in sick. It's only two lanes each way and goes through the squirrel hill tunnel and Pittsburghers hate tunnels.
posted by octothorpe at 7:05 AM on March 13, 2005

Hub and I have been using this site for years - a lifesaver.

Now when the hell are they going to follow the Chicago model and build a train or light rail down the center of the damn freeways??!!
posted by OhPuhLeez at 7:05 AM on March 13, 2005

For San Diego this caltrans web site has sensors on every freeway exit and delivers real time traffic information updated every 60 seconds.
posted by onekat at 9:21 AM on March 13, 2005

OhPuhLeez: I don't know if it was a tongue in cheek comment, but I don't think I can ever see the day when public transit is considered as a viable option by more than 20% of Angelinos. LA's structure (or lack of) leads to people living in the bizarrest locations compared to their place of work.

I've worked in an office in Studio City, and people were coming from downtown, Long Beach, Lancaster(!!), Ventura, Marina Del Rey, and Santa Clarita. Public transport will do you Studio City to Long Beach in about 1hr30, and downtown is only about 25m, but all the other places? Fuhgeddabout :)
posted by wackybrit at 7:50 PM on March 13, 2005

You can get traffic info in an always-on pocket-sized device for L. A. or Seattle.
posted by kindall at 7:57 PM on March 13, 2005

LA's structure (or lack of) leads to people living in the bizarrest locations compared to their place of work.

LAs sprawl is actually a result of it having originally had such a good public transport system.
posted by fshgrl at 3:45 AM on March 14, 2005

The usefulness of this tool to commuters is suspect...I can tell you what the 405 looks like from 4PM to 8:30PM...A parking lot. Seems like this is only useful to people that are not working 9 to 5s.

What would be infinitely more useful would be a city street traffic map...

"LA's structure (or lack of) leads to people living in the bizarrest locations compared to their place of work.

LAs sprawl is actually a result of it having originally had such a good public transport system."

Up until the 50's LA had a very useful public light rail system. Then the big auto companies bought out the system and paved it over...
posted by schyler523 at 9:20 AM on March 14, 2005

for those more inclined to street traffic L.A. city has a similar system for surface streets. while most of west hollywood isn't covered it's still pretty handy if you're trying to escape and there is a movie premier AND a show at the bowl.
posted by raygun21 at 12:20 PM on March 14, 2005