One reason often overlooked reason CBTC is problematic is that it provides management, lawyers and politicians the ability to reach forward and jam a broom handle in the spokes of the bike they are riding. Policy capture is the concept where an automation system allows "the powers that be" to implement policies that were previously impossible with a non-automated system. The most common example is on board announcements. While it would be difficult to go through the trouble of getting train operators to announce more than the next stop and "stand clear of the doors", an automated system can be programmed costlessly announce whatever management can think up, turning a generally quiet ride into a barrage of PSA's and nags. Well we have a new example of policy capture that stands ready to ruin SEPTA's Route 101 and 102 suburban trolleys.
As previously discussed, the new CBTC signaling is replacing a stop-go block system that first used two lamp ABS signals and later regularly placed interlockings to ensure train separation. Since the Routes 101 and 102 utilize interurban type equipment that can run in street traffic, there was no need for a complex ABS system as the trolley operators could see a stop signal ahead and then stop at it like they would a vehicular traffic signal. In this case CBTC should have allowed for more frequent operation as on the dedicated rights of way the trolleys would be able to run much closer together. Instead the technology allowed for policy capture.
While largely separated from road traffic, the Route 101 and 102 rights of way include many road crossings which are protected by crossbucks and traffic signals. Needless to say these are prone to the occasional trolley-motor vehicle accident. Attempts to install crossing gates to improve safety caused so much traffic congestion that the resulting public backlash not only halted the project, but saw the installed gates removed. This is the point where SEPTA could throw up its hands, say they tried and accept the occasional collision as a cost of car dependency, however this is where the CTBC system provided a hitherto impractical solution of enforcing a 10mph trolley speed at all road crossings.
 |
| Deactivated crossing gates. |
Sure, this could have been a operating rule, but such an awful policy would quickly be ignored by operators making SEPTA potentially liable for the negligence of road users. However CBTC enforcing the speeds at every single road crossing took operators out of the equation and reduced the implementation cost to nothing. The only problem was that a 30 minute trip become a 45 minute trip. It's not clear how this will affect the ridership, but the cost of an half hour per day is likely to push more people onto the roads.
 |
| CBTC beacon. |
It's hard to argue against appeals to safety and thinking of the children. That's why sometimes the only way to win is to not deploy technology that makes enforcement possible. SEPTA's Route 104 used to be a suburban streetcar like the current routes 101 and 102, but was converted to bus operation in 1958. Today that bus can now travel far more quickly than a limited stop rail line on a dedicated right of way because, for the time being, those buses have human operators that are allowed to use their judgement and skill. A similar situation has also been reported on Toronto's Fitch West light rail line with the new LRV's taking up to 20 minutes longer than the previous buses due to an enforced 15kph speed restriction at intersections.
