Drivable device for laying at least one flexible line, cable, cable-drawing empty conduit, or fluid transport hose underground, in particular below traffic routes or verges or strips running alongside roads, wherein a narrow trench respectively having a desired laying depth can be cut into the ground surface of the verge by means of a wheel milling cutter of a milling unit, the ground material milled out in this way is removed laterally, the cable or cables and the warning tape is laid in the trench in the correct position, wherein fine particulate ground surface material or cable sand is introduced into the trench for embedding the introduced line/cable or the like and the milled out ground surface material previously laterally removed can be reintroduced and compressed, - wherein the cable to be laid can be drawn by a front vehicle driving at a low speed and can be inserted into the cable trench just created synchronously with the driving speed of the front vehicle, and - wherein a quantity of fine particulate material or cable sand, matched to the respectively current driving speed, can be introduced into the cable trench continuously via an ejected ditch or similar which is routed via the cable trench, - wherein, in particular for laying cables along a curved traffic route, the front vehicle, which is designed as a carrier vehicle having a rear-side support frame which has a side extension unit having a milling unit with cutting wheel and having a towing formwork and cable insertion unit following the milling unit, overall forms a drivable, curved, mechanical complete or compact unit, within which the milling unit and with it the cutting wheel are laterally outwardly offset relative to the front vehicle, thus can be positioned laterally protruding over the contour of the front vehicle connected to the front vehicle via a first articulation or a rotary joint on the side extension unit with a substantially vertical axis of rotation relative to the side extension unit, laterally pivotable towards both sides respectively at an angle of up to ± 25°, in particular of up to ± 20°, and - wherein the towing formwork and cable insertion and cable sand introduction unit following the milling unit in turn is connected to the milling unit also via a second articulation or a rotary joint with a substantially vertical axis relative to the milling unit, laterally pivotable towards both sides, respectively at an angle of up to ± 25°, in particular of up to ± 20°, characterised in that - the milling unit, which is laterally pivotable at an angle and which has the cutting wheel, is connected to a side extension unit which is integrated with the front vehicle or in its support frame with control and drive elements and is in the form of a tube-in-tube system mounted on rollers, by way of an extension device which can be adapted, preferably hydraulically, to the topographical conditions predetermined by the current verge to be cut out, so as to be linearly laterally displaceable with respect to the front vehicle, at least towards one side. - wherein the cable to be laid can be drawn by a front vehicle driving at a low speed and can be inserted into the cable trench just created synchronously with the driving speed of the front vehicle, and - wherein a quantity of fine particulate material or cable sand, matched to the respectively current driving speed, can be introduced into the cable trench continuously via an ejected ditch or similar which is routed via the cable trench, - wherein, in particular for laying cables along a curved traffic route, the front vehicle, which is designed as a carrier vehicle having a rear-side support frame which has a side extension unit having a milling unit with cutting wheel and having a towing formwork and cable insertion unit following the milling unit, overall forms a drivable, curved, mechanical complete or compact unit, within which the milling unit and with it the cutting wheel are laterally outwardly offset relative to the front vehicle, thus can be positioned laterally protruding over the contour of the front vehicle connected to the front vehicle via a first articulation or a rotary joint on the side extension unit with a substantially vertical axis of rotation relative to the side extension unit, laterally pivotable towards both sides respectively at an angle of up to ± 25°, in particular of up to ± 20°, and - wherein the towing formwork and cable insertion and cable sand introduction unit following the milling unit in turn is connected to the milling unit also via a second articulation or a rotary joint with a substantially vertical axis relative to the milling unit, laterally pivotable towards both sides, respectively at an angle of up to ± 25°, in particular of up to ± 20°, characterised in that - the milling unit, which is laterally pivotable at an angle and which has the cutting wheel, is connected to a side extension unit which is integrated with the front vehicle or in its support frame with control and drive elements and is in the form of a tube-in-tube system mounted on rollers, by way of an extension device which can be adapted, preferably hydraulically, to the topographical conditions predetermined by the current verge to be cut out, so as to be linearly laterally displaceable with respect to the front vehicle, at least towards one side.