Not long time ago, Jarret Walker has written a post explaining the value of the isochrone maps, he presents as freedom maps: The freedom measure here is not that much about mobility than access: “how many new choices – jobs, shopping, schools, houses of worship or philosophy, sports facilities, and so on, are brought within a given travel time of how many people”-by a proposed project.
When it is time to build a new bridge across a river, this concept is usually clearly understood. When it is time to build a new transit line, it is far less the case, and eventually in Metro Vancouver it quickly boils down to who gonna get its fair share of rail tracks… that eventually dues to the fact that transit investments are not understood as transportation ones. Here below is an example of what additional freedom can be brought by a Broadway Skytrain (all isochrones are rough approximate and generated with mapnificent).
Approximation of how much more destination (in purple) can be reached in 15mn from Cambie#Broadway
What is also very important to understand is that a transit project is not necessarily reduced to serve the people living in its immediate vicinity:
The isochrone maps above are with a commute time of 30mn on way (average commute time). As presented above, they carry little more value than improved mobility, in the term of how much more square km of area become more accessible: a good metric for urban sprawl, but not necessarily for economic value of the project and development sustainability
To measure how much the accessibility is improved for how many, integration of different density maps are needed:
metro population density map and vancouver job density map
All that and more give how much new opportunities are provided for how many people.
Translink certainly use the above datas to predict the ridership of any transit project, but the presentation of it under a “map of freedom”, can eventually allow a better visual grasp of the potential, influence, and sensitivity to land planning of the investment.
To be sure, you have to agree with the premise, that giving opportunities access to people is a good thing:
Compact development and constrained development
In some circles idealizing a certain past, people could tend to confound these 2 notions: A urban form constraining the opportunity options, be to learn, work… is per nature demanding to its residents to do some sacrifices. Conversely, an employer having access to a smaller labor pool will have less chance to find an adequate match. That provides in fine an economy not capitalizing on its talents, hence unable to perform as well as it should….and the purpose of any transport investment in history has been to improve the economy efficiency of the regions it connects.
A compact development can be achieved by constraint-i.e. lack of communication link- or by well designed communication links, where people want live at some specific nodes, because it is where they get the maximum freedom, in term of opportunity to work, learn, shop…It is eventually what the isochrones above represent: Some regional town centers become more attractive because a Broadway line gives them
- Better connection connection between each other, that is noticeably the case of Richmond and Lougheed (and beyond Tricities),
- Access to the central Broadway area, which is the second concentration of job in Metro Vancouver after Downtown.
The regional benefits of the Broadway line are undeniable, and probably are much greater than the local benefits, but can the served area accommodate further population/job growth?
in those matter “land use” planning is key, and it is a common misconception that growth needs to be accommodated by further sprawl. The connected areas still have lot of reserve for infilling and densification, which can be leveraged on both potential future rapid transit stations and arterials serviced by local bus routes - Not only in Vancouver, but also in the regional nodes benefiting of the Broadway line, as seen before
Broadway at Fraser;in bad need of revitalization; offers tremendous opportunities for densification among other
The question is hence more how to enable this potential, which need to be quantified, this to allow the best return on investment.
 In that respect, See also What Would It Take? Carbon Neutral Cities, Jeremy Falud, February 15, 2012 (and “key quotes” at pricetag ) and “Creating Places for People — The Melbourne Experiences“, Rob Adams, at SFU October 4, 2011