Defining the Problems
You have only two project management problems here:
- How the client's communication preferences impact the project's budget or efficiency (if they do).
- Who bears the financial burden of travel costs.
There are other peripheral issues, but they are really more about how you feel about the client's communication style, or how you can communicate your own preferences in a professional manner. As your primary job is to manage the project effectively, these secondary issues should be carefully framed within the context of what's best for the project—asssuming you genuinely think that it's both professional and relevant to address them at all.
First, you should carefully measure the impact of the client's communication preferences on the project. Your post contains an emotional appeal, but no actual project metrics to support your position. When you say:
They can't grasp how to use email and phone to communicate project amendments and feedback...[T]his is a huge waste of time compared to emailing, phone, or instant message.
you are conveying a host of implicit assumptions, including the following.
- You are assuming that your clients are Luddites who are ignorant of the alternatives or incapable of effective communication. This assumption sets up an intrinsically adversarial relationship.
- You are assuming that time (Your time? Project time?) is being "wasted." This assumption is not valid unless backed by concrete metrics or quantifiable objectives.
- You are assuming that all modes of communication are equal. Effectiveness is very context-dependent.
Unless your contract spells out how feedback and change control are to be managed within the project, how you and the client agree to handle these issues is certainly negotiable. However, such changes should be based on more than your personal preferences; professionalism demands that significant process change be tied to observable data and clearly-articulated process-improvement objectives with measurable results.
This may be a legitimate issue if it represents a change in cost structure or scope from what was originally agreed to. For example, if your contract states that the project budget is all-inclusive, but included incorrect assumptions about the amount of travel that would be required, then your contracting process should be carefully reviewed and the issue gently raised with the client.
On the other hand, if the project was deliberately bid as a fixed-price contract with known travel requirements, then you may not have a legitimate recourse. That doesn't mean that you can't discuss it with the client; if reducing travel would provide a positive impact on the project, that's information the client should have in order to make an informed decision about what's most valuable to them (e.g. face-time or potential project efficiencies).
Whether or not cost-shifting is an option, travel is certainly a requirement that can impact a project's budget, schedule, or efficiency. However, it is up to you as the project manager to track any such impact with concrete metrics, and to bring a level of professionalism to process-improvement discussions that treats your personal preferences as a side issue.