Abstract: An assembly for use in drilling in earth borehole using a drill string including a drill bit comprising a first downhole motor having a rotor operatively connected to said drill bit, a second downhole motor distal said first downhole motor, said second downhole motor having a rotor with a passageway therethrough and a bypass valve operatively connected to the second downhole motor, the bypass valve having a first position permitting drilling fluid to flow through said passageway and a second position wherein drilling fluid is prevented from flowing through said passageway.

Abstract: A safety marker deployment system and method includes a plurality of safety markers removably associated with a motor vehicle in a laterally pre-positioned array substantially corresponding to a desired lateral position on a roadway. The safety markers can be removably disposed in an elongated container mountable to the motor vehicle. Each of a plurality of sequential ejectors is associated with one of the plurality of safety markers to sequentially deploy the safety markers, while the vehicle is moving, in a longitudinal configuration substantially corresponding to a desired longitudinal position on the roadway. The safety markers include a displaceable material disposed in a compliant compartment, and a visual indicator extending upwardly from the compliant compartment.