What are the factors that go in to earning more credits? I roll along making my 50 credits about every 45s to 1.25 minutes but that really seems to be it. Is the accrual rate effected by speed limits, activities such as horns for crossings etc.? I have not noticed anything yet. Does collecting all the items generate anything other than an accomplishment? Are there any other ways to increase the income from a scenario or service? Thanks.