Melissa De Alejandro Montalvo
The role of guided buses schemes in achieving a sustainable transportation system
One of the many challenges in the present day is the need to steer away from inefficient means of transportation and to find different solutions to fulfil the transportation needs of individuals in the most sustainable way possible. There are many possible alternatives to choose from, and guided bus schemes are one of them. A guided bus is a type of bus rapid transit that features a dedicated bus lane with a guiding kerb. The kerb allows for the dedicated lane to be narrower, which is of great importance in highly dense areas and being on a dedicated lane helps reduce the time spent on traffic, improving the reliability of the bus service.
Despite the perceived advantages of guided buses, it is not clear how does it fit in a sustainable transportation system. This research explores different aspects of a guided bus schemes, in order to assess the authenticity of the claims of its sustainability. The basis for this research will be the longest guided busway in the world, the 24 km long Cambridgeshire Guided Busway. In order to assess the impact of the Cambridgeshire Scheme, there have been several different studies undertaken.
As a part of the analysis, there will be an assessment of the carbon emissions inherent to the construction of the busway. This is being done by calculating the embodied carbon of the project, using a methodology based on the PAS 2050 procedure. The result will be compared to one of the alternatives considered on the planning stage of this scheme. The purpose of this comparison is to determine if there are any advantages on choosing the Guided Busway scheme over its alternative.
Another part of the study will be an accounting of the carbon emissions during the operation of the Busway. These emissions will be compared to the emissions from the Bus Route 55 from Cambridge to Huntingdon that was replaced by the new scheme. The emissions will be calculated using the Emissions Factors 2009 from the Department of Transport, which accounts for differences on emissions for different speeds. There are two different scenarios explored, one according to the timetables and another one with data from the operation scenario. The purpose of this analysis is to assess if being on a dedicated lane is causing a difference on vehicle speed that translates into a reduction in carbon emissions.
The results of the different studies will provide a base to assess of the sustainability claims of a guided bus scheme. There will be a discussion on other key factors to the sustainability claims of the scheme. The results from this analysis will then be extrapolated in order to assess its applicability in other contexts.