Interesting developments in traffic monitoring

About a couple of years ago I had a conversation with someone who did a bunch of contract work on traffic monitoring systems - he was networking all the traffic cameras and radar together and providing a nice web interface with Traffic 511 like monitoring of congestion data. The added bonus was you could actually get a live feed of traffic on your favorite streets - his system was for Alameda county and hence monitored mostly city streets, not freeways. During the meeting he talked about how much cheaper his implementation was than the tens of millions CalTrans spent on their system which used data read from FasTrak transponders in people's cars. When he mentioned the trip time data that Traffic 511 was providing (and is now shown on electronic signs by the freeway) I asked him if they were doing the dumb thing of quoting actual measured journey times - it turns out that was how they do it.

I say it is dumb because if you are in Oakland (say) and trying to get to San Francisco and there is a wreck then you wont know about it from estimated journey times until someone has completed the entire trip - which could be a long time. And as each person arrives at the destination their data is as old as their complete journey time. Now a way around this is to break journeys into much smaller segments and integrate along the path continuously but apparently they weren't doing that either, except perhaps at very gross city to city levels.

Ideally as soon as there is a change in traffic flow past a point, as measured by velocity and number of cars at that point you should be able to feed that information into a model, combined with everything else you know about traffic on the roads and generate a new estimate very quickly - without waiting for cars to drive an entire segment. As a physicist by training that just seems like basic fluid dynamics to me... And you can feed in other information about known changes to the configuration of "pipes", ie. the roads. So when CHP calls in that they will shut down a freeway for 15 minutes to bring a medivac, or take it down to 2 lanes while they sweep debris, or open up Hwy 580 to trucks for a while then you should be able to feed that data in an make travel time prediction adjustments immediately. Thus the effect of a wreck in Oakland can instantaneously be feed back to someone in Milpitas traveling to Berkeley and allow them to choose an alternate route.

Anyway two years ago most of the clever stuff you could do really depended on having a lot of data about where cars were which either meant outfitting a lot of cars with telemetry systems or getting access to the FasTrak transponder data. Well of course two years on we have an increasing number of gadgets flying up and down freeways that already have GPS and data links built-in - they are called phones. So I kick myself for not thinking about what Nokia is doing in a trial where they are using standard N95 GPS equipped phones to see if they can predict traffic flow information - not just travel times, but predict information like I suggested. Plus the benefit is this system can be extremely cheap to set up since people like participating in such "social" applications (cf. Seti@Home and Folding@Home), even more so if they are actually of benefit to themselves. I think it will only be a matter of months before some open source project, quite likely sponsored by Google (and running on Android) will produce an app and centralized traffic monitoring/prediction services to the masses.

The only issue is that do really great prediction actually requires more than simply measurement - for this reason I think the initial data provided will be just the same level as Traffic 511, just measuring speeds on the freeway. To do really smart stuff requires complicated routing calculations and someone like Google (say) with access to that, and smart people to crunch the numbers and build models will be needed to build the software. All good stuff to build into Google Maps right and make it even more of a killer app - especially when mobile.

XP Unlimited still going strong

A year ago I blogged about a product I'd found called XP Unlimited that let you get true multiuser access to a single Windows XP (Pro) machine via remote desktop. That post is the #1 most visited post on my blog - it is listed on the first page of Google results for "XP Unlimited" and has had almost 1,500 page views in the last year. So I thought I'd post an update on XP Unlimited...

I'm here to report that XP Unlimited the product is still going strong, I still think it rocks, I still use it myself on my home computer network, and I since have got several small businesses that I do IT support for to use it after showing them the product and setting them up with a VPN and the free 3-user evaluation version.

One of those businesses is a food import company that has three local users who travel quite a bit and then two remote users on different parts of the country. They use a local Access database extensively to manage their client accounts and orders but having no web access to that data proved a big problem for them. Facing an expensive rewrite of the application as a web based tool, or switching over to an expensive proprietary solution that may not ideally fit their needs (like SugarCRM or Salesforce.com) they were stuck. I'd already set up a VPN for them that let them access critical files, but the database just wouldn't work over a Windows remote file system, it would takes literally minutes to switch from screen to screen.

So I set them up with an XP Unlimited eval license running on their central "server" which wasn't a server at all, just a desktop that hosted their database files locally, had MS Access on it and had a gigabyte of memory (which was a lot at the time they bought it three years ago). Now they could have their users connect to their VPN (we used OpenVPN because it was SSL based and hence would always be able to pass through WiFi hot spot networks) and then connect to their central server via Remote Desktop. Once logged into the server they could run their database application and because Remote Desktop optimizes screen output for the bandwidth available it was very effective. Also database apps, including theirs are typically not graphical intensive and use a lot of text and solid blocks of color, all of which are transfered very efficiently with Remote Desktop. The result was basically a miracle for the company - even when overseas in the UK where roundtrip ping times are 150ms or more it worked like a charm and they were very happy and they purchased a five user license for the product.

Some additional advantages of the XP Unlimited based solution was that it required the minimum of configuration on remote machines - all they had to do was install the OpenVPN software along with a key for that machine and pull up Remote Desktop which is included on all XP machines - even XP Home. Previously when trying to give them access to files on the server I had to get them to set up a proper user name, configure file sharing and set a password that matched a user name and password on the central server - all a big pain, especially if they had a password they didn't want to change or reveal to me. With XP Unlimited I just created a local user on the server machine, set a default password with an appropriate policy and let them have at it - they could change it to whatever they wanted. And I could easily decide what groups to put them in to restrict access to other machines on the central office network.

The only disadvantage was this was all a bit too high tech for some users - the idea of remotely logging into a machine can be confusing for those that have never seen it, and really hard to explain in words. A work around for users that only need the company database is I could get XP Unlimited to only allow access to the database, and start it when they logged in, so basically they could click a remote desktop icon on their laptop (or whatever), enter a username and password and they would see a new window containing only the database app. To them it looked just like any other application and it was much less confusing. Ultimately I stopped setting up accounts like this because most users also needed access to some shared files which was slow over the VPN and Windows remote filesystem. It was basically so much faster for them to use remote desktop to browse for the file on the server, open it in Word or whatever on the server and view it all remotely - hence all the company's remote users now log in and see a full Windows desktop afterwards. An additional benefit of this is the work they do there is always backed up and instantly available to others, plus if their VPN or network connection drops they can just log back in again later and their desktop is still there exactly as they left it - brilliant.

Lastly the central "server machine" that is really a pretty lowly P4 machine regularly handles four concurrent user session and the one local user reports no significant impact on her work so they haven't had to invest a penny on new hardware to support these remote users - and more importantly didn't have to do that costly re-write of their database app which would probably have cost them thousands in contract time.

The only disadvantage of XP Unlimited I can see is that with the plummeting value of the US Dollar vs the Euro (and most other currencies) XP Unlimited is quite a bit more expensive that when I first looked at it in early 2007. The most basic five user license will cost you € 112 which is currently around $164 (not including credit card currency exchange fees). But I think that is still a good price, especially compared to the cost of Windows Small Business Server ($500 plus per client/user fees) and XP Unlimited is really a very good and cost effective solution for small businesses that don't already have a Windows Server based solution.

I personally think XP Unlimited should have a full supported home user version with 3 user licence in the $20 to $50 range, although arguably from the terms of use you can use their demo version for non-commercial use at no charge so this is not necessary, but many businesses just don't like using demo versions (like betas!) and need to have somewhere to go for support.

For home and small biz users I think they could bundle the product with some easy to use remote acess VPN technology like Hamachi and add a lot of value and get more paying customers using it. Selling to smaller scale users like consumers and small businesses makes sense to me as so many of the larger potential customers that might buy their "enterprise" products will already be using Windows Server with corporate VPN setups (or just the SSL secured Remote Desktop) and have no real need for XP Unlimited. With the sharp increase of always on home computers and small business "servers" there is an increasing need for users to be able to do remote management and access of their machines easily from wherever they are, only pricing and better marketing lay between them and a lot of eager customers!

Of course at any time Microsoft could catch a clue and enable multi-user simultaneous desktop access for home users of XP and Vista but that doesn't seem to be likely any time soon because there are just too many small businesses using those products that might otherwise have to move to Windows SBS. With such a feature they could just use a cheap $200 Linux machine with a terminal server client and get all the benefits of an XP and Office machine without the additional cost!

In the mean time I continue to recommend XP Unlimited whole heartedly, so why not just download a demo copy and give it a try!