74% of Europeans live and move every day in cities, and 40% of the total CO2emissions from transport is caused by urban mobility. The decarbonisation of urban transport can therefore produce a substantial reduction in total CO2emissions. Cities have proposed various measures to reduce CO2 emissions from mobility, concentrating particularly on reducing private individual transport (car) by offering a range of alternatives.Sustainable Urban Mobility Plans (SUMPs) are not new in Europe, as numerous precedents in France, UK, Italy and Germany have now been underway for a decade. SUMPs propose a strategy to reduce dependence on private cars by imposing a series of measures.As the plans were designed for the long term (ten to fifteen years), it is only natural to question their effectiveness after a certain time has elapsed. However, there is little literature on this issue. To fill this gap this article proposes a methodology to evaluate Sustainable Urban Mobility Plans using indicators to assess the current situation of the city in terms of the effectiveness of the measures implemented, focusing on the specific case of the city of Burgos in Spain, where the Sustainable Urban Mobility Plan was introduced in 2005, and on the results based on the proposed methodology.CO2 savings are always the primary target of a SUMP. Most assessments highlight changes in behaviour or public perception, but contain no in-depth analysis of cost-effectiveness. This paper aims to calculate a cost analysis for each tonnes of CO2 saved. This methodology is used in other fields such as lighting and energy, but not in transport due to its complexity. However, effectiveness ratios can be calculated with the available data on modal shift and investments in the SUMP, taking into account the costs as a whole. Other methodologies to determine external cost savings are included in the proposed methodology to achieve a more accurate ratio and consider more external factors.

The aim was to reduce missions and noise pollution, the promotion of public spaces recovered for the citizens, promoting accessibility, recycling of materials to produce new cleaner fuels and in general terms the change to a greener City through the sustainable mobility.

It was structured in three points:

· The first was focusing on Public Transport with the renewal of the fleet to a more sustainable one, currently 75% of them running with biodiesel and 25% with Compressed Natural Gas and with an average age of only two years old. A campaign to collect used cooking oil for conversion into biodiesel was promoted. Another important point was the accessibility, now the public transport is all 100% accessible, with low ramps and oral and visual electric panels to give advice. The project was also focused on the accessibility at the bus stops, giving more clear information and adding real time electronic information panels. Finally, the lines were changed to transform them into more efficient ones and with better frequencies. This has resulted in an increase of 8% in the use of the buses by the citizens.

· The second point was the pedestrianization process of nearly four square kilometers of the center, preventing the movement of vehicles and creating an entirely new space, returning to the citizens the public space for strolling, shopping or going to bars and enjoying the terraces without fear, noise or smoke. 16 electronic bollards were placed and 2.000 cards were distributed to residents and neighbors, taxi drivers or police to enter the area. Along with these measures security cameras were installed to control the area 24 hours a day 7 days a week from the new traffic control center, which also gives real-time advice and suggests to the drivers about where to leave the car in a cleaner or sustainable way(using the underground parking), or how to avoid traffic jams and problems. Currently 98% of citizens have a favorable opinion to the traffic restriction and the reduction of pollution, fumes and hazards in the area is 95%.

· Finally, some actions were focused on alternative means of transport. It was installed a free bike loan system with 16 points which has got now after three years of use over 5,000 users. Measures were accompanied by measures in favor of cycling as a day by day transport, such as installing bicycle parking (more than 200 new racks) or the introduction of the bicycle lane. Burgos is nowadays the Spanish city with the highest percentage of bike lane kilometer per 10,000 inhabitants. The bicycle use as a routine has grown from a residual 0.5% in 2005 to almost 5%today.

Other actions included the promotion of car pooling, with 400 users; the promotion of private collective vehicle aimed, above all, to move to industrial areas (with 2,000 users); or the collective taxi.

All was performed under the collaboration of citizens, with all the stakeholders involved from the outset of the proceedings, and with targeted dissemination and promotion in order to change citizens' mind.

Through this initiative, the experience has achieved global significance with the CIVITAS City of the Year Award at the European level, or the Energy Globe Award at global scale, considered the Nobel of sustainability.