Have you taken a look at Meteor’s Assets docs? You might want to consider using the Assets API instead, and working within a /private directory. Then when you need to get the absolute path of your asset directory/subdirectory, you can use Assets.absoluteFilePath(assetPath) (which will work anywhere you deploy it).
The static assets are image files in my case. Having them in a private directory, wouldn’t that make them not “openly” available to the client and thus causing more network requests/traffic than having them in a public directory?