Usability is fast becoming a new metric for search ranking by the algorithms. The ease in which a visitor can engage with your site and find what they are looking for tells Google and others a lot about the quality of your site and the value of the information contained within in the website. Interestingly, usability also can have a big impact on your conversion rate.
Usability is more than just design. It goes to the mindset of the individual who has come to your door. The challenge is that each user is unique and there is no way to customize a website down to the individual. You need to think in terms of your target market, what they are doing and what information they are seeking when they visit you. Are they out and about looking for actionable information to do something now, like find your location, buy tickets, or find a map, etc.? Or are they at home conducting research for an upcoming trip? It is important to create a path to information for the intent of your audience. And then make sure it is the information they are looking for.
Conversion rate is largely impacted by the way users move through your site. Are you making it easy for the user to know what to do next? This is a bit of a dance. You are trying to impact user behavior and at the same time provide information based on user behavior. How do you do that?
This is where usability and conversion come together. You need to plan out a path through your site that makes sense to both your business goals and the user, and is easy and clear. That is the ultimate synergy of high usability and high conversion rate.
How do you know if you have reached the ultimate synergy? Test and measure.