This investigation has the aim to provide advice and support on the implementation of smart city projects at European Union level. A quantitative feasibility study - strengths, weaknesses, opportunities and threats analysis - based on more than one hundred previous experiences of smart city projects in Europe, indicates a certain difficulty in carrying out the investigated efforts. Results show that the main obstacle is the environment external to the analysed activities (opportunities and threats), while issues internal (strengths and weaknesses) to the investigated projects appear to facilitate their execution. The following were identified as main barriers (weaknesses and threats): i.) subsidies, ii.) communication between project participants and the public, and iii.) expertise in designing new technologies and solutions. In contrast, the most effective drivers (strengths and opportunities) are i.) public participation, ii.) cooperation between different stakeholders, and iii.) political commitment over the long term. Public participation is not only the most powerful driver, but also the most utilized factor to overcome the detected barriers.