Funding and capacity limitations are indeed the cause of problems, but they're not root causes. They're symptomatic of broken political systems, broken business models, and a moribund industry that often delivers shockingly poor value for money.
Similarly, more money is a solution, but it's not necessarily a good solution, if the majority of that money will be lost due to graft, mistakes, and inefficiencies. (McKinsey estimates that around $1 Trillion dollars is wasted every year, across all classes of infrastructure.[1])
(Note: this assessment has a lot of regional variance. It is mostly true in most of America, mostly false in Singapore, and has various levels of applicability in between.)
Anyhow, before simply throwing more money at the problem, I'd recommend taking a look at how the politics, business models, and industry workflows can be shaken up a bit.
1: http://www.mckinsey.com/industries/capital-projects-and-infr...
Afaik, the Vancouver skytrain still uses the original OS/2 software to run.
2. Funding/Capacity.
3. More money.