Notes for Figure 6H-36 6H-36(CA—Typical Application 3Lane Shift on a Freeway

Guidance:

  1. The lane shift should be used when the work space extends into either the right-hand or left-hand lane of a divided highway and it is not practical, for capacity reasons, to reduce the number of available lanes.

Support:

 

  1. When a lane shift is accomplished by using:
  1. geometry that meets the design speed at which the permanent highway was designed,
  2. full normal cross-section (full lane width and full shoulders), and
  3. complete pavement markings, then only the initial general work-zone warning sign is required.

Guidance:

 

  1. When the conditions in Note 2 are not met, the information shown in the typical application should bemployed and all the following notes apply.

Standard:

 

  1. Temporary traffic barriers, if used, shall comply with the provisions of Section 6F.85.
  2. The barrier shall not be placed along the shifting taper. The lane shall first be shifted usinchannelizing devices and pavement markings.

Guidance:

 

  1. A warning sign should be used to show the changed alignment.

Standard:

 

  1. The number of lanes illustrated on the Reverse Curve signs shall be the same as the number of through lanes available to road users, and the direction of the reverse curves shall be appropriately illustrated.

Option:

 

  1. Where two or more lanes are being shifted, a W1-4 (or W1-3) sign with an ALL LANES (W24-1cP) plaque (see Figure 6F-4) may shall be used instead of a sign that illustrates the number of lanes. The Reverse Curve (W1­-4) sign shall be used instead of the Reverse Curve (W1-­4a & W1­-4b) signs which shows the number of lanes. 

Option:

 

  1. Where more than three lanes are being shifted, the Reverse Curve (or Turn) sign may be rectangular.

Guidance:

 

  1. Where the shifted section is longer than 600 feet, one set of Reverse Curve signs should be used to show the initial shift and a second set should be used to show the return to the normal alignment. If the tangent distance along the temporary diversion is less than 600 feet, a Double Reverse Curve sign should be used instead of the first Reverse Curve sign, and the second Reverse Curve sign should be omitted. Use the Reverse Curve (W1­-4) signs for both locations instead of the Double Reverse Curve (W24-­1) sign.  
  2. If a STAY IN LANE sign is used, then solid white lane lines should be used.

Standard:

 

  1. The minimum width of the shoulder lane shall be 10 feet.
  2. For long-term stationary work, existing conflicting pavement markings shall be removed antemporary markings shall be installed before traffic patterns are changed.

Option:

 

  1. For short-term stationary work, lanes may be delineated by channelizing devices or removable pavement markings instead of temporary markings.

Guidance:

 

  1. If the shoulder cannot adequately accommodate trucks, trucks should be directed to use the travel lanes.
  2. The use of a barrier should be based on engineering judgment.

Option:

 

  1. Type C Steady-Burn warning lights may be placed on channelizing devices and the barrier parallel to the edge of the pavement for nighttime lane closures.

Option:

  1. Detail 11 (see Figure 3A­102(CA)) may be used instead of the temporary solid white lane line, which is shown in Figure 6H-­36(CA).

Support:

  1. See Section 6F.106(CA) for use of the Slow For The Cone Zone (SC19(CA) and SC20(CA)) Signs.Guidance:
  2. All advance warning signs should be placed so that the path of travel for bicycles is not blocked, while maintaining visibility for road users.
  3. When existing accommodations for bicycle travel are disrupted or closed in a long­term duration project (see Section 6G.02) and the roadway width is inadequate for allowing bicyclists and motor vehicles to travel side by side, the Bicycle Crossing (W11­-1) sign and the SHARE THE ROAD (W16­-1P) plaque should be used to advise motorists of the presence of bicyclists in the travel way lanes.
  4. Except for short durations and mobile operations, when a highway shoulder is occupied and bicyclists would be sharing a lane with vehicular traffic, as a result of the TTC zone, speed reduction countermeasures should be used to reduce traffic speeds in the TTC zone. Refer to Sections 6C.01 and 6D.03.
  5. Except for short durations and mobile operations, when a highway shoulder is occupied and bicyclists would be sharing a lane with vehicular traffic, as a result of the TTC zone, before narrowing the outside lane other measures such as widening the outside shoulder to allow bicyclists and motor vehicles to travel side by side through the TTC zone should be considered.
  6. If traffic volumes make it feasible, the two left lanes should be merged into one lane to avoid using the shoulder as a traveled way lane and allowing continued use for emergency purposes and bicycle travel.
  7. When existing accommodations for bicycle travel are disrupted or closed in a long­term duration project (see Section 6G.02) and the roadway width is inadequate for allowing bicyclists and motor vehicles to travel side by side, a separate path should be considered for bicyclists.

Notes for Figure 6H-37—Typical Application 3Double Lane Closure on a Freeway

Standard:

 

  1. An arrow board shall be used when a freeway lane is closed. When more than one freeway lane iclosed, a separate arrow board shall be used for each closed lane.

Guidance:

 

  1. Ordinarily, the preferred position for the second arrow board is in the closed exterior lane at the upstream end of the second merging taper. However, the second arrow board should be placed in the closed interior lane at the downstream end of the second merging taper in the following situations:
  1. When a shadow vehicle is used in the interior closed lane, and the second arrow board is mounted on the shadow vehicle;
  2. If alignment or other conditions create any confusion as to which lane is closed by the second arrow board; and
  3. When the first arrow board is placed in the closed exterior lane at the downstream end of the first merging taper (the alternative position when the shoulder is narrow).

Standard

  1. All advance warning signs mounted on portable supports shall be equipped with at least two flags or a flashing warning beacon. Each flag shall be at least 16 X16 inches in size and shall be orange or red in color. Flashing warning beacons (Section 6F.83) shall be used to call attention to the initial warning signs during hours of darkness. Flashing warning beacons is optional during daytime operations.

Option:

  1. A truck-mounted attenuator may be used on the shadow vehicle.
  2. If a paved shoulder having a minimum width of 10 feet and sufficient strength is available, the left and adjacent interior lanes may be closed and vehicular traffic carried around the work space on the right-hand lane and a right-hand shoulder.

Guidance:

 

  1. When a shoulder lane is used that cannot adequately accommodate trucks, trucks should be directed to use the normal travel lanes.

Standard:

  1. 3 cones or 2 Type II barricades shall be placed transversely across each closed lane at end of each merging taper and every 2000 feet throughout the lane closure.
  2. On freeways, maximum spacing of channelizing devices shall be 50 feet in advance warning and transition areas, 100 feet in activity and termination areas (see figure 6C­1).

Guidance:

  1. LANE CLOSED C30(CA) sign should be placed every 2000 feet throughout the lane closure adjacent to the open lane within the closed lane.

Support:

  1. For State highways, see Department of Transportation’s Standard Plan T10. See Section 1A.11 for information regarding this publication. 
 

Notes for Figure 6H-39—Typical Application 3Median Crossover on a Freeway

Standard:

 

  1. Channelizing devices or temporary traffic barriers shall be used to separate opposing vehicular traffic.
  2. An arrow board shall be used when a freeway lane is closed. When more than one freeway lane iclosed, a separate arrow board shall be used for each closed lane.

Guidance:

 

  1. For long-term work on high-speed, high-volume highways, consideration should be given to using temporary traffic barrier to separate opposing vehicular traffic.

Option:

  1. When a temporary traffic barrier is used to separate opposing vehicular traffic, the Two-Way Traffic, Do Not Pass, KEEP RIGHT, and DO NOT ENTER signs may be eliminated.
  2. The alignment of the crossover may be designed as a reverse curve.

Guidance:

 

  1. When the crossover follows a curved alignment, the design criteria contained in the AASHTO “Policy on the Geometric Design of Highways and Streets” (see Section 1A.11) should be used.
  2. When channelizing devices have the potential of leading vehicular traffic out of the intended traffic space, the channelizing devices should be extended a distance in feet of 2.0 times the speed limit in mph beyond the downstream end of the transition area as depicted.
  3. Where channelizing devices are used, the Two-Way Traffic signs should be repeated every 1 mile.

Option:

 

  1. NEXT XX MILES Supplemental Distance plaques may be used with the Two-Way Traffic signs, where XX is the distance to the downstream end of the two-way section. 

Support:

 

  1. When the distance is sufficiently short that road users entering the section can see the downstream end of the section, they are less likely to forget that there is opposing vehicular traffic.
  2. The sign legends for the four pairs of signs approaching the lane closure for the non-crossover direction of travel are not shown. They are similar to the series shown for the crossover direction, except that the left lane is closed.

Notes for Figure 6H-38—Typical Application 3Interior Lane Closure on a Freeway

Standard:

 

  1.   An arrow board shall be used when a freeway lane is closed. When more than one freeway lane iclosed, a separate arrow board shall be used for each closed lane.
  2.   If temporary traffic barriers are installed, they shall comply with the provisions and requirements in Section 6F.85.
  3.   The barrier shall not be placed along the shifting taper. The lane shall first be shifted usinchannelizing devices and pavement markings.
  4.   For long-term stationary work, existing conflicting pavement markings shall be removed antemporary markings shall be installed before traffic patterns are changed.

 

Guidance:

 

  1.   For a long-term closure, a barrier should be used to provide additional safety to the operation in the closed interior lane. A buffer space should be used at the upstream end of the closed interior lane.
  2.   The first arrow board displaying an arrow pointing to the ight should be on the left-hand shoulder at the beginning of the taper. The arrow board displaying a double arrow should be centered in the closed interior lane and placed at the downstream end of the shifting taper.
  3.   If the two arrow boards create confusion, the 2L distance between the end of the merging taper and beginning of the shift taper should be extended so that road users can focus on one arrow board at a time.
  4.   The placement of signs should not obstruct or obscure arrow boards.
  5.   For long-term use, the dashed lane lines should be made solid white in the two-lane section.

 

Option:

 

  1.   As an alternative to initially closing the left-hand lane, as shown in the typical application, the right-hand lane may be closed in advance of the interior lane closure with appropriate channelization and signs.
  2.   A short, single row of channelizing devices in advance of the vehicular traffic split to restrict vehiculatraffic to their respective lanes may be added.
  3.   DO NOT PASS signs may be used.
  4.   If a paved shoulder having a minimum width of 10 feet and sufficient strength is available, the left-hand and center lanes may be closed and motor vehicle traffic carried around the work space on the right-hand lane and a right-hand shoulder.

 

Guidance:

 

    14. When a shoulder lane is used that cannot adequately accommodate trucks, trucks should be directed to use the normal travel lanes.

 

Standard:

     This typical application is deleted for application and shall not be used on freeways in California. Whenever an interior lane needs to be closed on freeways, all adjacent lane(s) to one side of this lane shall be closed as illustrated in Figure 6H­37.

Support:

     For state highways, see Department of Transportation’s Standard Plan T10, T10A and T14. For interior lane closure on Freeways using mobile operation, see Department of Transportation’s Standard Plan T16. See Section 1A.11 for information regarding this publication. 

 

Notes for Figure 6H-40—Typical Application 40 Median Crossover for an Entrance Ramp

Guidance:

1. The typical application illustrated should be used for carrying an entrance ramp across a closed directional roadway of a divided highway.

2. A temporary acceleration lane should be used to facilitate merging.

3. When used, the YIELD or STOP sign should be located far enough forward to provide adequate sight distance of oncoming mainline vehicular traffic to select an acceptable gap, but should not be located so far forward that motorists will be encouraged to stop in the path of the mainline traffic. If needed, yield or stop lines should be installed across the ramp to indicate the point at which road users should yield or stop. Also, a longer acceleration lane should be provided beyond the sign to reduce the gap size needed.

Option:

4. If vehicular traffic conditions allow, the ramp may be closed.

5. A broken edge line may be carried across the temporary entrance ramp to assist in defining the through vehicular traffic lane.

6. When a temporary traffic barrier is used to separate opposing vehicular traffic, the Two-Way Traffic signs and the DO NOT ENTER signs may be eliminated.