Publishing in a Procedia journal versus a 'proper' one
The journal information site says the following:

What is the Transportation Research Procedia?
The Transportation Research Procedia is an open access product focusing entirely on publishing full sets of conference proceedings, enabling fast, world-wide dissemination so that conference delegates can publish their papers in a dedicated online issue on ScienceDirect. (see link: Website)

Which means that this is actually NOT A JOURNAL. And, essentially not equivalent to a journal in any sense. It publishes the proceedings of the recently organized conferences in the related fields. Simply put, it indexes online the papers which are accepted and presented in the conferences.
Why it can not get an impact factor?
Actually, it can not; because, it is not a single proceeding. It is a collection of multiple proceedings. Say for example, International conf. on Transportation Engineering A, International Conf. on Civil Aviation (these are just names, ignore).
Even if it tries to get any impact factor, then it would be completely biased given the number of conferences and their corresponding standards of accepted papers.