Ambient Human-to-Human Communication

In the current technological landscape colored by environmental and security concerns the logic of replacing traveling by technical means of communications is undisputable. For example, consider a comparison between a normal family car and a video conference system with two laptop computers connected over the Internet. The power consumption of the car is approximately 25kW while the two computers and their share of the power consumption in the intermediate routers in total is in the range of 50W. Therefore, to meet a person using a car at an one hour driving distance is equivalent to 1000 hours of video conference. The difference in the costs is also increasing. An estimate on the same cost difference between travel and video conference twenty years ago gave only three days of continuous video conference for the same situation [29]. The cost of video conference depends on the duration of the session while traveling depends only on the distance. However, in a strict economical and environmental sense even a five minute trip by a car in 2008 becomes more economical than a video conference only when the meeting lasts more than three and half days. It is often suggested that the transportation and telecommunications are strongly coupled, or complementary. The telephone is an important means of making appointments and therefore enabling and justifying more travel, but at the same time travel increases the need for communications. For example, Short et al [97] give an example where the opening of a bridge in the UK led to a significant increase in the telephone traffic between the two previously separated areas. In fact, a recent analysis by Choo and Mokhtarian [23] on travel and telephony data in the USA since 1950’s indicates that travel triggers more need for telecommunication than telephony leads to travel.