Background information from the developer, Eric Masaba:

Texxi is short for "The (shared) Taxi you Text" and "Transit Exchange for the XXI Century".

We got Texxi to work more easily in more sparse locales, which goes against the conventional wisdom which states that people need a dense city area.

Our approach uses a Demand Responsive Transit Exchange to allow people who commute to buy multiple trips in a taxi far ahead of time.

It can be used to group people into taxis, minivans or any other sort of vehicle including private jets.

Deployments have been made in Liverpool (2006) and the Isle of Wight (2008).

What we found while deploying Texxi was that the system we were trying to model changed its nature as the Texxi "good" became accepted. This rapidly invalidated many modelling assumptions since the propensity and intention to use the Texxi service was directly related to its availability and perceived reliability far more than its cost.

In Liverpool, during our first large deployment in March 2006 to September 2006, we had attempted to operate from one location (a nightclub) and market directly to customers on their way in and out of the club. We had also festooned the club with banners and advertising and had invested in thousands of flyers. We had two very attractive promotional models at the entrance to the club handing out flyers. We spent on 28 large billboards around the city and we ran a radio advert for 5 weeks. We got some PR writeups in the local newspapers and we attempted to engage local promotion agencies to do flyer drops. In short we followed all the usual, "marketing advice" from "marketing professionals".

This proved to be a disastrous strategy. We found that it was impossible to get people to notice what Texxi was or how it worked. They were too drunk to follow instructions, although they had actual transport difficulties. Thus our models for uptake "fell over" spectacularly. We even tried giving away free trips but found that this did not help people to value the service. This was March 2006 - Sep 2006, although PR and warm up started in October 2005. Our biggest single problem was a PR agent who wanted to tell us what to do rather than listening to us. She ignored everything we said and executed precisely the correct strategy to spend the most money with the least results.

We then had a lot of interest from Australia and Singapore so we went over there to plan for a deployment. This is called our "Demand Mapping Exercise" phase. We had interest from the City of Brisbane but not from the cab firms there. We thus tried to work with the Limousine companies instead. In December 2007 I returned to the UK to do a talk for the Professors at UWE Bristol's Centre for Transportation Studies (CTS).

Fast forward to our deployment for 6 months on the Isle of Wight, July 2008 - December 2008. This time we invested in a large set of promotion teams. We produced higher quality handout collateral and we restricted its distribution to people who become customers, i.e., actually followed the sign-up process and travelled. We "incentivised" the "Street Teams" to land more customers. We ran some local PR in the newspapers and on the radio.

We moved 5 times as many people (700) for 1/10th the cost as in Liverpool in an area whose "potential" was far less. We never used billboards or flyers. We got one mention on the radio. In Liverpool we ran on Friday and Saturday nights. In Ryde (Isle of Wight), only on Friday.

Liverpool has 500,000+ people (1.5m in the conurbation), 22,000 taxis and is a must go destination in the Northwest of England for partygoers. The town of Ryde on the Isle of Wight has 20,000 people and perhaps 50 cabs. The whole Island has 135,000 people and is completely bounded by water. Most people in the UK have never heard of Ryde.

Lessons Learned. Ignore all "conventional marketing approaches". Focus on what works on the street and perception level.

The "Demand" for shared trips will increase as knowledge spreads that such a service exists and can be relied upon. This means that the behaviours of customers completely changes within a very short timescale. We caused a depression in normal taxi trip prices in Ryde within 3 - 6 weeks, so much so that we had threats of violence from other firms within the 6 month deployment. This makes historical data of limited use in predicting what will happen once uptake happens.

SQL is not an easy language to model the flow of trips in real time. Since I come from a banking and engineering background, I am familiar with matrices and like languages which process lists. The @Formula language in LotusNotes/Domino and the "views" construct fulfil these type of operations remarkably well. The whole trip engine we used is based on Lotus Domino - the same technology that runs our website and email services as well as serves as our development engine. (University of Uppsala used to use it). In fact Domino IS the database as well as the processing engine.

We decided to treat taxi drivers as small farm holders and therefore consider how we would approach their problems from an agricultural perspective. The answer would be an agricultural or produce exchange which would serve as an open marketplace. Since what a taxi driver produces is "trip fulfilment", the marketplace would have to "come to the producer". This is now very easy with modern technology. We wondered why there was not a formalised "Taxi Transit Exchange", so we set about to create it. This is the "Demand Responsive Transit Exchange" or the "Transit Exchange for the XXI Century" (TE XXI).

By mapping the transit problem to exchange-space, we can use some tricks from finance - like liquidity provision and market makers. Thus in order to prime demand, we can purchase "empty seats" (perform "stuffups") by open market operations. This serves to give customers confidence over a buildup period that their requests for transport will be met and will serve to make sure that we can get to a critical mass.

Texxi has developed a smartphone app, described here.