You can use the travel forecast as a diagnosis of a city and alternatives generation as a part of the solution package. I propose to Brazilian cities the choice of mode share targets - desirable participation of mass transit, bicycle and travel by walking - in the whole of daily trips.

Salam All,

Generally speaking, Forecast comes first then you need to think about alternatives that fit with your forecast. But the Urban transportation problem is bigger than this, and it should be taken in a comprehensive view.  all the phases should be taking together as a one process. don't forget that different Urban problems need different solution alternatives.

Regards

I agree with my colleagues: travel forecast comes first. But we should be alert. As a diagnosis, travel forecast also embodies the current situation. So, let's put a filter on this, in order to learn the lessons of the past. In other words, travel forecast should be taken carefully...

So can we say that by surveying the ccurrent situation, a phase of searching for possible alternatives ( alternative generation phase) might come next to understand what available options we have (i.e.in the area under study), and to analyze what effects each alternative has (selected criteria or measures based on the objectives of the study).Then the next step might be the estimation of both the cost of each alternative and the travel demand, so that to evaluate each of those alternatives and select the most feasible option?

The magnitude of travel demand (brought by travel forecasting) influences the alternatives development. Imagine if you have more than 60,000 passenger per hour in one direction: Then, only trains' systems can meet this demand, right? On the other hand, in cases of something between 60,000 to 30,000, a BRT could be the solution, for exemple.  

as other said the travel forecast comes first cause it can be said that what we're forecasting is a kind of our goal, and step by step we can define objectives to meet and in each step we gotta evaluate the model that we have made to come to this conclusion that are we moving forward or not. 

forecasting land use then forecasting trips generation