Tuesday, February 8, 2011

Increasing Transit Frequency

One of the biggest drawbacks of Edmonton's and the majority of transit system, is that transit routes seldom have frequency higher that 30 minutes.  Patrons of Edmonton's LRT line already see the benefits of having higher frequency routes, Edmonton's LRT sees about 100,000 patrons or 10% of Edmonton's population in one day.   Part of the LRT's popularity can be explained due to its frequency not slowing past 15 minutes.  During peak times the LRT runs at 5 minute frequency, 10 minute frequency during midday and early evening , and 15 minute intervals during late evening. 

When a route's frequency is high it does not matter as much when you miss a bus. With infrequent routes wait times at most are 1 hour or 30 minutes, if you just missed your bus you have to wait the whole interval for the next bus to arrive.  Whereas when a route has quicker intervals such as five minutes, the most you will ever have to wait for the next bus is 5 minutes.  Your maximum possible wait time is always equal to your frequency, unless of course your bus is late.

This is highly convenient as you do not have to carefully plan your routes and trips for errands.  If I want to go somewhere that is only accessible by bus I have to find out when the next bus will come to take me there,  since I do not want to wait 30 minutes in -20°C weather.  I also have to find out multiple departure times at the end point to head home, since I do not know exactly when I will be done my errands.

On top of all that I need to arrive at my bus stop 5-10 minutes early, since bus drivers do not always respect the fact that their customers actually depend on transit services as their main mode of transportation.  A bus should never be allowed to arrive earlier than the specified route timing, the bus in a perfect world should wait at the bus stop until the designated time has passed.  This fault should improve with the installation of GPS tracking services soon to come to Edmonton and Calgary transit,  as supervisors will suddenly now have a way to track a bus drivers performance.  However it may also happen since the bus may have been delayed by 10 minutes, so this brings your total wait times up to at least 15 minutes by including the 5 minutes that you had to arrive early to just to make sure you could catch your bus.  This does not include walking times that you spend to get to your bus stop, destination or bus transfer.

However with higher frequencies I would be highly more likely to simply walk to the bus stop without carefully planning my trip, since I know I would at most only be waiting 5 or 10 minutes.  The fact is that it makes for much more convenient, and stress free transit commuting.

What leads to this design of infrequent routings?  A large part has to do with the nostalgic notion that transit planners possess, that the bus service has to reach every doorstep with little or most likely no transfers.  City planning also changed after WWII, as City Planners threw the knowledge proper city planning from our forefathers out the window.  If you look at most cities downtown cores which were developed ages ago, you will notice a similarity.  Most downtown's and mature neighbourhoods were designed in grid like patterns with roads running north-south, and east-west. 

Downtown Edmonton Grid Style Road Network

However if you were to look at the road network for the newly minted neighbourhoods, you will notice a similarity as well.  Suburban planning dictates that the design of its road network focus on making car commutes as light free as possible.  This results in a spaghetti like mess of roads that wind and curve, complete with cul-de-sac dead ends. 

Example of Edmonton's Suburban Road Network
This means that there are often only a few main entrance ways into a suburban neighbourhood.  If you want to get to a specific location within the neighbourhood, the only way to get there is to follow the winding roads that take you to 10 other places before you get to where you want to be.  This also applies to pedestrians since they have to deal with fences and insufficient access points between cul-de-sacs.  Suburban road networks are a nightmare for bus routes.  In order to service the neighbourhood a bus route has to utilize the poorly planned winding roads, which increases the travel time.

Transit planners have a belief that its citizens hate transfers (where you have to get off one bus to catch another).  Well the fact is that we do hate them, when they are planned incorrectly.  When you have to wait 30 minutes for one bus only to have to get off to wait for another bus for 30 minutes, yeah...nobody is going to A) enjoy that or B) want to do that.  So since transit planners believe that its patrons hate transfers, they do everything in their power to design routes to eliminate them.  This causes routes to turn off of a road to serve a neighbourhood only to turn back onto the road it left later.  This sort of planning only serves to add travel time to those that don't live in the said neighbourhood, a route that could have went straight down the road had to add a series of zig-zags.  This type of planning is only compounded by the lack of access into and out of suburban neighbourhoods.

Example of Calgary's Route 33 Deviation from Straight Route

How could we rectify this?  To start from a blank slate, every major roadway should be assigned its own high frequency straight route.  These routes will follow the road as much as possible, directly between bus and LRT stations along dedicated bus lanes when possible.  I would like to compare bus routes in north east Edmonton, to show how much more efficient the bus system could be by implementing this type of routing.

Existing North-East Edmonton Routing

I have selected four existing routes (11-blue, 182-green, 180-red, 152-black) to study between Clareview/Belvedere and Northgate stations. The relevant information for these routes is tabulated below.  With the routes current frequency and travel times, a total of 10 buses are required at any point in time. 

Direct North-East Edmonton Routing

I have drawn up what four direct routes (153 Ave.-black, 144 Ave.-blue, 137 Ave.-red, 132 Ave.-green)  would look like utilizing more direct routing.  The first thing you will notice is that the total distance for the four direct routes drops 14 km or 33%. Both sets of routing have approximately similar spacing of 400-500 m or 10 minutes walking distance.  The new route trip times average at about 15 minutes.  With a higher frequency of 15 minute for all routes you would only need 8 buses to operate the four routes at any given time.  This is a 20% drop in the number of operating buses, which will see savings in maintenance and fuel since you are not running as many buses. 

I would now like to apply this on a city wide scale to generate some a rough idea of how this would improve service on a whole.  The existing LRT line that runs north-south across the entire city is approximately 20 km.  So we can say that the city is roughly 20 km by 20 km.  Now lets take divide the city into routes 400 m apart (Why 400 m? 400 m or 10 minutes is the widely accepted maximum walking distance transit users will walk to reach a bus route).  This means that you will have approximately 50 west-east and 50 north-south city-wide routes.  Edmonton's LRT takes approximately 33 minutes to complete one way of its city wide trek, so we will assume that each city-wide route takes 35 min to complete one way.  This amounts to approximately 7000 minutes of bus travel time to complete a full loop for each 100 routes.  The city currently has a fleet of 940 buses.  So if you were to implement 15 minute frequencies for each route you would only need to utilize 500 buses or 50% of our current fleet, and 700 buses or 75% of our current fleet for 10 minute frequency.  This means that you can provide city wide 10 minute bus service with direct routing, with an surplus of 240 buses under current operating restraints.  These extra 240 buses can be used to increase service in specific areas, or to have spares for when buses need to undergo repairs.

With direct routing under existing fleet capabilities, Edmonton would be able to provide its customers with city-wide 10 minute frequencies.  You would only have to walk 10 minutes north-south or west-east to stumble upon a bus route, and patrons would only have a maximum waiting time of 10 minutes for any bus. By implementing direct routing you make your system more convenient since patrons do not need to look up bus routings, if they want to head north or south they simply walk east or west 10 minutes at most to find a route.  You simplify the commuting for transit riders as they no longer have to worry about missing their bus as much, and do not have to research their route options.

1 comment:

  1. I am more thinking 800 metres, because at any one point, you could walk 400 metres from it, and so to have a radius of 400 metres, the diameter is 800. 400 metres is a bit dense except in the city centre. Assuming that you might be willing to walk a little further and make it 500 metres, not too far I believe, about 5.5 minutes at 1.5 metres per second, the frequency of stopping is more reasonable. If you made a right isosceles triangle with 500 metres as the legs, then the hypotenuse is 700 metres, so you are only ever 700 metres away from any bus stop in the city. At 400 metre spacings we are looking at ~550 metre distances from any location in the city.

    The bus priority projects need queue jumps and traffic light priority and removal of as many traffic lights as possible via roundabouts or replacing pedestrian crossings with lights with RRFB flashing lights, raised crosswalks, curb extentions and median refuges, to make it as quick as possible. The buses can also have raised stops to reduce the need of kneeling. Under 500 metre spacings we're looking at about 4000 stops.

    And don't forget that you can make the waiting time more pleasant too. Wifi routers is good, a shelter or at least a bench is nice to have. Some busy stops could have heaters in the winter. Add bicycles to the mix, so add a bike rack or two per stop. Quite good.