Preliminary Design of Bus Rapid Transit in the Southfield/Jefferies C

GM Tlansportation Systems 4.0 INTERMEDIATE SERVICE IN THE SOUTHFIELD-GREENFIELD CORRIDOR The potential transit demand in the Southfield-Greenfield corridor, as estimated in Stage I, is not sufficient to support the non-stop (or one-stop) BRT service envisioned for the Southfield-Jeffries corridor, An intermediate stopping service is therefore proposed to provide improved transit service in the corridor, This section of the final report presents the analyses which led to the design of the Intermediate Service, Following an over view of the system, the evaluation of alternative routes and implementations is described. Then a summary of the corridor demand analysis, including consideration of potential demand for Fairlane, is presented, Finally, system cost estimates are presented. 4.1 Overview of Greenfield Intermediate Service The objective of the Intermediate Service is to provide a higher level of service in the Southfield-Greenfield corridor than is currently being provided by local buses with a system that can be deployed quiGkly and with low capital investment. The system which is proposed to satisfy this objective is an intermediate level bus service operating on Greenfield Road between Southfield and Dearborn, The system is designed to provide improved travel time for relatively long transit trips (two miles or more) by stopping only at major cross-streets and by operating with traffic signal pre-emption. The proposed system operates at constant 12-minute headway throughout the day from 7:00a.m. to 9:00p.m. During periods of peak work trip demand (7:00 to 10:00 a.m. and 3:00 to 6:00p.m.), the route is configured so that direct distribution service is provided to employment sites in Dearborn and in Southfield along Northwestern Highway. A schematic representation of this route, showing stop locations, is shown in Figure 4-1. In addition, a shuttle bus operating at 15- to 20-minute headways between Fairlane Town Center and the Ford Route Plant is proposed. During off-peak periods, Southfield and Dearborn Distribution Routes are eliminated, and the Intermediate Service operates be tween Northland and Fairlane, Access to the Northland terminal is provided by the Oakland County Feeder System described earlier in this report. The existing DDOT local bus system is assume<:! to provide feeder service to the line-haul portion of the Intermediate line. Off-peak access to the Fairlane terminal from Dearborn employment sites is provided by a proposed Dearborn Shuttle which operates on a headway of about 35 minutes. 4,2 System Synthesis This section describes the evaluation of alternatives which led to the selection of Green field as the line-haul route for the Intermediate Service. The distribution routes proposed for Southfield and Dearborn are also described. 4-1 GM Transportation Systems CORRIDOR BOUNDARY e PROPOSED BUS STOPS II Mil•--+----, -" ....J t [--~-- Figure 4-1 Schematic of Greenfield Intermediate Service Route 4-2 GM Transportation Systems 4.2. 1 Alternative Bus Priority Treatments Two alternative line-haul routes, one using Southfield end the other using Greenfield, were considered in the design of the Intermediate Service. Alternative bus priority treatments on these two routes were considered in detail in Stage I. The evaluation of alternatives in Stage I was concerned with selecting an essentially non-stop BRT route assuming that a relatively Iorge number of buses would be in operation in the peak hour. Since the Intermediate Service involves o fewer number of buses operating throughout the doy and stopping ot approximately one-mile intervals, the alternative priority treatments for each route were re-evaluated. It wos concluded that the best Intermediate Service implementation alternative for Southfield is, essentially, the one that was recommended in Stage I. The alternative involves mixed-traffic operation with the existing signal progression system in Oakland County and mixed-traffic operation without special priority on the freeway. It is not recommended that Southfield Rood be widened north of Lincoln as proposed in Stage I because the volume of buses operating an the Intermediate Service route (5 per hour as indicated in Section 4.3 of this report) is not sufficient to iusti fy the construction cost. The best alternative implementation for the Greenfield route is also similar to the one recommended in Stage I. The route is the some as the Southfield alternative north of ' Eight Mile Rood but follows Greenfield instead of Southfield Freeway in Detroit. The i implementation alternative recommended for the Greenfield portion of the route is mixed-traffic operation with traffic signal pre-emption. Pre-emption was not recommend ed in Stage I because the volume of BRT buses operating on the route would totally disrupt cross-street progression. This is not considered to be a serious disadvantage with the Intermediate Service implementation because the average interval between buses (6 minutes -5 buses per hour in each direction) is equal to several cycle times of the signal. Less then 25 percent of the cycles will be pre-empted thus retaining the benefits of progression for most of the traffic. Signals at all intersections need not be equiped with pre-emption equipment to realize o significant increase in bus speeds. Signals ot streets with particularly high traffic flows (e.g., Grand River) may be exempt from pre-emption. 4.2.2 Route Selection Concurrent with the re-evaluation of implementation alternatives, the design of the pro posed Oakland County Feeder System was being completed. As indicated in Section 3.4, the proposed feeder system is focused on Northland, and the routes use both Southfield and Greenfield to access Northland Center. The proposed headway on each route is about 20 minutes in the peak period and ranges from 30 to 40 minutes during off-peak periods. The combined headway on Southfield Rood between Northland and Fourteen Mile is less than 20 minutes even during base periods. It was determined that this new service is sufficient to service the portion of the 4-3 GM Transportation Systems corridor north of Northland. Therefore, the alternative routes were evaluated on the basis of providing line-haul service between Northland and Fairlane Center in Dearborn. The alternative route using Southfield runs southeast on the Lodge Service Drive From Northland to Eight Mile, west on Eight Mile to Southfield, south on Southfield Freeway to Ford Road, south on Southfield Service Drive to Hubbard Drive, and then west on Hubbard to Fairlane Center. Buses operating on this route would exit the Freeway at each mile road to make intermediate stops on the Service Drive. They would operate on the Service Drive between Seven Mile and McNichols to serve Mercy College. The alternative route using Greenfield runs southeast on the Lodge Service Drive From Northland to Greenfield, south on Greenfield to Hubbard Drive, and then west on Hubbard to Fairlane Center. Buses operating on this route would make intermediate stops at the mile roads plus Outer Drive and Grand River. The two routes were evaluated on the basis of the six Factors listed in Table 4-1. The First Factor, estimated demand potential, is a measure of the total number of trips in the corridor to destinations potentially served by each route. TALUS zones located adjacent to each route were identified as destinations. Other zones located in Southfield and Dearborn which were assumed to be served by Intermediate Service distribution routes, were also identified as potential destinations. Table 4-2 lists the destinations which were assumed For each route. The number of'trips attracted to these destinations by all modes during the moming peak period was determined From the TALUS Survey data. The modal split program developed in Stage I was used to estimate the number of Intermediate Service riders assuming each route. The resulting transit trips were screened to eliminate trips of less than two miles. It is assumed that these short trips are served by local buses rather than by the intermediate stopping service. As Table 4-1 indicates, slightly larger number of trips (both total trips and screened transit trips) are attracted to destinations adjacent to the Southfield route in the morning peak period. The second evaluation Factor that was considered is the estimated average bus speed on each route. Average bus speeds For the off-peak period were calculated based on a number of assumptions. These assumptions are summarized in Table 4-3. As indicated in the evaluation matrix (Table 4-1), the Southfield route results in a very slight overall speed advantage even though the potential maximum speed on the Freeway is much greater than that on Greenfield. The low acceleration capability of a transit coach nearly eliminates the advantage of using a high speed link when operating between closely spaced stops. The estimated cost of making the physical changes necessary to implement the Interme diate Service on each route was considered. Initio lly 1 no modifications to existing fcc il ities are required for the Southfield Route. However, if the proposed ramp metering system, SCANDI, is implemented on the Southfield Freeway, exclusive bus access ramps will be required to allow buses to bypass the auto queue at the ramp meters. Based on conceptua I ramp designs and cost estimates generated during Phase I of the Michigan Bus Rapid Transit Demonstration Program, the estimated cost of queue by-pass ramps for the Southfield Freeway is $35,000 each. Since approximately

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