Electronic guidance/control technologies offer greater potential for improving safety and efficiency of transportation needs. An electronic guidance system can provide guidance information to the operator, assist the operator to carry out partial steering task or perform fully automated steering as part of an integrated automated vehicle control system. Electronic guidance technologies have been applied for transit guidance applications where buses are electronically guided to achieve performance similar to railways. Benefits were gained to allow buses to travel on narrower lanes or tunnels and to reduce stress on drivers. Application examples of electronic guidance system also include on-going development of lane departure warning systems and advanced snowplow guidance systems under US DOT's Intelligent Vehicle Initiative (IVI) program. It is a general belief that a fully automated lateral control system should have high reliability against all factors that can potentially disable the operation. Specifically, a lateral guidance system must be able to inform the operator when system fails while an automated lateral control system must be able to work with all weather and road surface conditions and must be fail-safe. A critical element of the electronic guidance system is the reference/sensing subsystem which provides vehicle's lateral position relative to lane references - to allow driver or the lateral control system to know where the vehicle is and, ideally, where to go. Magnetic reference/sensing technologies demonstrated great potential for lateral guidance and control applications. Current development of magnetic reference/sensing technologies involves two approaches: magnetic marker and magnetic tape based technologies. This paper will focus on the discussion of the magnetic marker system. It will also present some comparative analysis results between the magnetic marker and magnetic tape technologies.