A travel plan is a package of measures implemented by an organization to encourage people who travel to/from that organization to do so by means other than driving alone by private car. This paper advances two principal arguments: firstly, that the planning system and maximum parking standards as part of it are the main factors leading to travel plan development in England today; and, secondly, that the difficulties of using the planning system in this way means that there is a risk that many of these travel plans are unlikely to have a great deal of influence on travel patterns, thus making more unlikely the full achievement of the predictions of travel plans’ overall impacts on travel behavior change, as contained in (1). The paper presents results from a survey of planning and transport authorities in England, which obtained a 62% response rate from the 139 authorities contacted. The survey found that the planning process (as opposed to voluntary efforts) is indeed the main means by which travel plans are now secured. In addition, maximum parking standards were shown to have a major influence on travel plan formation for organizations going through the planning process. However, there are reasons to doubt that all of the travel plans secured through the planning process are effective, because: Many local authorities use only planning conditions and not the more flexible (but complex) obligations which would allow more complex travel plans to be secured. There is a lack of monitoring of travel plans in many authorities. There is evidence that in many authority areas there are travel plans in breach of legal agreements, but these breaches are not enforced, due to a lack of monitoring, resources, and other organizational issues.