Of the 60 buses, 20 would be new, additional buses that are needed for the expansion of services the AAATA will be offering starting Aug. 24. Those services will be funded with proceeds from a new millage authorized by voters on May 6, 2014. The other buses will replace existing buses that are nearing the end of their useful life.

The large spread between the minimum and maximum cost per bus is due to the incremental price difference between a hybrid electric drive system and a conventional clean diesel drive, which is nearly $200,000. According to the minutes of the Aug. 12, 2014 meeting of the AAATA’s planning and development committee, the extra cost of a hybrid bus over the life of the bus is $138,604. That figure includes cost comparison data relating to the upfront capital and fuel costs of both technologies.

Of the AAATA’s existing 80 buses, 52 use hybrid technology. The ongoing debate among AAATA board members on choice of technology is based in part on the AAATA’s own experience with hybrid buses. The 5-year warranty has expired on the AAATA’s oldest hybrids, which has required a contingency budget for their future repairs. And manufacturers have now shortened their warranty periods for new hybrid buses from five to two years. That shorter warranty period will translate into greater costs to the AAATA for repairs.

According to AAATA staff cited in the PDC meeting minutes, the hybrid buses’ lower emission levels are a benefit of hybrid technology. However, the Environmental Protection Agency’s ongoing emission reduction standards now ensure that all new transit buses – whether hybrid or conventional – have very low emissions. On average, hybrid buses run at a noise level of 72 dB(A) compared to 75 dB(A) for conventional buses.

So the AAATA board has not yet made a final decision on the choice between hybrid technology and conventional clean diesel. The order for the first 27 buses from Gillig – which was also given approval at the board’s Aug. 21 meeting – leaves open the decision on the choice of technology.  Of the 27 that are being ordered, 14 are replacement buses and 13 are buses needed for the service expansion.

The board would need to act by November 2014 on choosing the technology for the bus order. The choice to order hybrid technology could be based on the identification of grants that might pay for the cost differential of that technology. Delivery of the buses is planned for October 2015.

Here’s how the bus acquisition schedule breaks down:

              OCT   FEB   JAN   JAN   OCT  
Purpose      2015  2016  2017  2018  2019  TOT
============================================== 
Rplcmt buses
(now elig)     4                             4                          
Rplcmt buses 
(elig 11/15)  10           5     4          19
Rplcmt buses
(elig 11/19)                           15   15 
5YTIP Svc Exp 
(8/2015)       4                             4
5YTIP Svc Exp        
(6/2016)             9                       9
5YTIP Svc Exp  
(8/2017)                   7                 7 
==============================================
TOTAL                                       58

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This brief was filed from the AAATA headquarters building, where the board held its Aug. 21, 2014 meeting – due to the closure of its regular meeting location at the downtown location of the Ann Arbor District Library. The library building was closed to due to the repair of the public elevator.