Transport is Australia's third largest and second fastest growing source of greenhouse gas (GHG) emissions. The road transport sector makes up 88 percent of total transport emissions and the projected emissions increase from 1990 to 2020 is 64 percent. Achieving prospective emission reduction targets will pose major challenges for the road transport sector. This paper investigates two targets for reducing Australian road transport greenhouse gas emissions, and what they might mean for the sector: emissions in 2020 being 20 percent below 2000 levels; and emissions in 2050 being 80 percent below 2000 levels. Six ways in which emissions might be reduced to achieve these targets are considered. The analysis suggests that major behavioural and technological changes will be required to deliver significant emission reductions, with very substantial reductions in vehicle emission intensity being absolutely vital to making major inroads in road transport GHG emissions.

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Although passengers dislike transferring, efficient transit systems should facilitate transfers to provide auto-competitive citywide access. This paper reviews bus transfer behavior in Melbourne, Australia, to understand causal factors. It also explores network effects: high ridership associated with frequent services or simple (grid) networks or both. Half of bus users make transfers, mostly to rail. The number of tram and bus transfers is generally low; however, in inner and central business district areas where trams run, they dominate. The young, students, males, commuters, and riders with periodical or full-fare tickets have high bus transfer rates. Middle-aged and older groups, off-peak riders, riders on shopping trips, and concession ticket holders have lower rates. Weekday peak hour commuters have high transfer rates. Frequent or longer-distance bus route types, simpler or straight route alignments, commuter services, and routes that require transfers have high transfer rates. Schedule coordination with rail increases transfer rates, but only a little. A modest but significant relationship (R2 = .25) between the volume of transfer trips and average service frequency was shown. High transfer volumes occur where at least one route has a frequency of 10 min or better. Current bus plans propose a 15-min-based grid route network. These findings suggest that major routes need at least 10-min headways to generate high transfer rates. A high bus transfer subnetwork was identified with features consistent with the network effect; however, conclusive proof of the network effect remains elusive. In simple terms the network effect, though intriguing, remains an unsubstantiated theory that informs good practice but should be treated with caution when applied in the real world.

Ridership growth is now a major objective of transit systems throughout the world. Increasing the quantity of service provided is acknowledged as a means of increasing ridership, but it is an expensive means. Previous research showed that ridership growth returns about a third to a half the percentage growth in expanded service kilometers invested (a short-run elasticity of 0.3 to 0.5) for local bus route improvements. Little research has examined the impact of extending hours of service into the evening. Research was done to explore why higher-than-expected ridership growth was shown in a project in which bus route operating hours were extended into weekday and weekend evenings. Elasticities of more than 0.8 were experienced on weekend services, generally above previous experience. Analysis found that where services were extended into evening hours, about half the ridership growth occurred during the daytime when no changes to services were implemented. It is hypothesized that this is caused by enabling daytime outbound-from-home trips such that riders can return in the evening by using buses. Investigation of travel-behavior patterns established that much outbound daytime travel was tied to return travel in the evening. The patterns examined were consistent with this hypothesis. Implications of these findings, including suggestions for further research in this field, are discussed.

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