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26 YIELD AUTHORIZED AUTHORIZED SHOULDER AUTHORIZED SHOULDER TO SHOULDER BEGIN (1) BUSES ONLY BUSES BUSES BUSES ONLY ONLY END ON WATCH SHOULDER FOR BUSES ON (2) SHOULDER ER U D S L CH ON BUSE FOR SHO WAT (3) (2) AUTHORIZED AUTHORIZED SHOULDER SHOULDER AUTHORIZED SHOULDER BUSES BUSES ONLY ONLY END BEGIN BUSES ONLY 200 FT NOTES: (1) Required only at signalized intersections where right turn on red is permitted. (2) Install near midpoint when zone exceeds 3 mi and continues at approximately 1.5 mi spacing. (3) Install as needed to warn bus drivers where shoulder is less than 10 ft. FIGURE 17 Typical shoulder signage for bus use. removed, granular base adjusted, and increased bitumi- Figure 21 shows the regional context for the BBS and nous depth replaced. Signing and striping improve- Figure 22 depicts how the BBS feeds the West Falls Church ments are also required. The estimated cost for this Metrorail Station. Transit buses (not other buses or vans) work is between $32,500 and $41,500, plus signing and can use the emergency shoulder only when necessary to striping costs. bypass mainline congestion Monday through Friday Condition five--Shoulder width is inadequate; widen- between 4 p.m. and 8 p.m. (originally from 5 p.m. to 7 p.m., ing and depth replacement are required. Signing and but extended after an initial test period proved operations striping improvements are also required. The estimated were running well and there was a definite advantage to cost for this work is between $42,000 and $66,000 per extending). Because the speed limit on the shoulder is mile, plus signing and striping costs. 25 mph, bus drivers have no incentive to using the shoulder unless mainline speeds drop below that level. The main rea- son for the queues along the eastbound Dulles Connector CASE STUDY 2--FALLS CHURCH, VIRGINIA during the BBS hours is the difficulty motorists have merg- ing onto congested eastbound I-66. The emergency shoulder was widened along a 1.3-mi por- tion of eastbound VA-267 (known as the Dulles Connector The project was designed in coordination with the Vir- along this stretch), between the Magarity Road overpass ginia State Police (VSP) and Metropolitan Washington (just downstream of the Route 123 eastbound on-ramp) and Airports Authority [MWAA, which owns the right-of-way; the off-ramp to the West Falls Church Metrorail station. Virginia DOT (VDOT) operates the facility under agreement

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27 FIGURE 18 BBS signage: Shoulder--Authorized Buses Only. with MWAA]. VDOT obtained approval from FHWA be- cause design exceptions were necessary for the narrow inside shoulder above a bridge. Narrowing the inside shoulder was FIGURE 19 BBS signage: Watch for Buses on Shoulder. considered preferable to narrowing mainline lanes. VSP stressed the need to keep the shoulder looking like an emer- gency shoulder; therefore, a double solid white line was used to separate the mainline traffic lanes from the BBS shoulder (the initial pavement markings using dashed lines at the be- ginning and end of the segment were corrected, because they seemed to "invite" unfamiliar commuters to use the shoul- der). VSP keeps copies of the executed letters of under- standing from the "authorized" transit users so that they can refer to them if necessary for enforcement. An additional sign is located toward the end of the shoul- der that advises bus drivers to yield to off-ramp traffic. Virginia also operates a general traffic shoulder lane proj- ect on I-66 near the Dulles Access Road BBS project. Time- restricted use of this general traffic lane is defined more boldly than the signage used for the BBS facilities. During the shoulder's initial trial period and before ex- tending the shoulder hours of operation from 5 p.m. to 7 p.m. to 4 p.m. to 8 p.m., Fairfax County (whose buses are the main beneficiaries of the shoulder) conducted, a study to deter- mine number, classification, and speed of vehicles using the shoulder. Some corrective enforcement measures were needed (a few passenger cars were using the shoulder and a few buses were traveling at more than 25 mph). The follow- FIGURE 20 BBS signage: Yield to Buses on Shoulder.