Urban Street Design with DMURS Sean McGrath Senior Executive Engineer Fingal County Council
Urban versus Rural Design Rural Road Design Prefer higher speed Release constraints Work within fence line Urban Road and Street Design Prefer lower speeds - depends on place Allow (encourage?) constraints Work outside fence/kerb line (urban context)
March 2014
Speed and Design TRL (UK) reports 322, 325 and 551 Driver speed based on visual, psychological interpretation of the street. Legislation and regulation play a secondary role.
Speed and Urban Design DMURS analysed 9,500 RSA Free Speed Surveys and extent of hard and soft measures Glasilawn Road Abbey Park Delwood Road Lwr. Kilmacud Road (R825) Clonkeen Road (R827) Morehampton Road (N11) Navan Road (N3) Stillorgan Road (N11)
Speed and Urban Design Speed is a function of Urban Design Stillorgan Road (60 km/h) Ave. 71.6 km/h Lwr Kilmacud Rd (50 km/h) Ave. 48.7 km/h Brian Rd (50 km/h) Ave. 31.0 km/h Frequency and Extent of Psychological and Physical Measures
Design and Low Speed
DMURS Practical Implications Street Networks (3.3.1) Filtered permeability Orthogonal (Fig 3.8) Curvilinear Organic
Using images or content with text Use a single clear image or graphic that illustrates your point Keep your points short and succinct Use bold for emphasis Dept. Name
Dublin in Comparison to Similar Cities Difference is mainly walking and cycling, not public transport 100% 90% 80% 70% 60% P ubl i c T r anspor t 50% Wal k/ Cycl e V ehi cl e 40% 30% 20% 10% 0% Dubl i n (1.2 A mster dam M uni ch (1.3 V i enna (1.6 Copenhagen M adr i d (3.2 mi l l i on) (0.8 mi l l i on) mi l l i on) mi l l i on) (1.9 mi l l i on) mi l l i on)
Cork in Comparison to Similar Cities Difference is mainly walking and cycling, not public transport 100% 90% 80% 70% 60% 50% 40% P ubl i c T r anspor t Wal k/ Cycl e V ehi cl e 30% 20% 10% 0% Cor k (0.2 Fr ei bur g Odense (0.19 San Gr az (0.26 Gr oni ngen M al mo (0.3 mi l l i on) (0.22 mi l l i on) Sebasti an mi l l i on) (0.18 mi l l i on) mi l l i on) (0.18 mi l l i on) mi l l i on)
DMURS Practical Implications Traffic Congestion (3.4.2) No new roads in urban centres cost, environmental reasons Maximise efficient use of road space (Fig 3.25) Accept some level of congestion is inevitable
DMURS Practical Implications Relief Roads (3.4.4) High capacity, but not necessarily high speed Longer distance traffic, especially HGVs Take traffic away from urban centres Inner Relief Road (Fig 3.31) Maintain sense of place Minimise severance Outer Relief Road (Fig 3.32) Separate from urban area Strategically planned (SDZ, Local Area Plan)
DMURS Practical Implications Relief Roads (3.4.4) High capacity, but not necessarily high speed Longer distance traffic, especially HGVs Take traffic away from urban centres Inner Relief Road (Fig 3.31) Maintain sense of place Minimise severance Outer Relief Road (Fig 3.32) Separate from urban area Strategically planned (SDZ, Local Area Plan)
DMURS Practical Implications Signing and Lining (4.2.4) Traffic Signs Manual Advises against over-provision of signs (1.1.10) shall or must, should and may (1.1.12) Minimise signage, esp. on local streets Better to have self-regulating design
Local Transport Note 2/09 There is no conclusive evidence that the inclusion of PGR at any type of pedestrian crossing or junction has any statistically significant effect on safety
DMURS Practical Implications Materials and Finishes (4.2.6) Define space, calm traffic, and improve legibility Reduce the need for barriers, signing and lining Need not be expensive
DMURS Practical Implications Planting (4.2.7) Provide softer landscape especially in suburbs, neighbourhoods (Fig 4.28) Consider size and types of trees Coordinate with SUDs
DMURS Practical Implications Pedestrians and cyclists (4.3) Footway widths 1.8m 4.0m (Fig 4.34) Pedestrian crossings (4.3.2) Zebras for moderate flows (Fig 4.37) Informal (raised?) courtesy (Fig 4.38) Avoid staggered crossings Minimise crossing distances Provide refuges (with PBUs at signals)
DMURS Practical Implications Corner Radii (4.3.3) Reduce pedestrian crossing distances Reduce vehicle speeds (Fig 4.42) Allow large vehicles to cross centrelines
DMURS Practical Implications Pedestrianised and shared surfaces (4.3.4) Full pedestrianisation (Figs 4.46) High activity through day and evening Retail, commercial and cultural centres Shared surfaces (Figs 4.46, 4.47) Transport function is low (eg homezones) Careful use of materials No kerbs(?) Minimise carriageway width and entry radii
DMURS Practical Implications Carriageway widths (4.4.1) Arterial and link streets lane widths min: 3.0m, standard: 3.25m, max: 3.5m Local streets 5.0m - 5.5m carriageway Local shared street 4.8m carriageway Boulevard (Fig 4.55)
DMURS Practical Implications Junction Design (4.4.3) Balanced approach not just car capacity Reduce kerb radii Omit left turn slips (Fig 2.8) Signals Ped crossings on all arms Include ped, bike, bus delays in optimisation Minimise cycle times
DMURS Practical Implications Junction Design (cont d) Roundabouts Large roundabouts not appropriate Difficult for pedestrians and bikes Limited capacity Land take Consider compact/continental roundabouts
DMURS Practical Implications Visibility distances (4.4.4) Much lower than DMRB (Table 4.2) Reaction time 1.5 seconds, not 2 seconds Deceleration rate 0.45g, not 0.25g Alignment (4.4.6) Arterial and Link Streets: retain directness Local Streets: speed reducing curves (Fig 4.65)
DMURS Practical Implications Sight Stopping Distances (metres) Design Speed 30 40 50 60 DMRB - 50 70 90 DMURS 23 33 45 59
DMURS Practical Implications Horizontal and Vertical Defections (4.4.7) To slow traffic without undue discomfort Horizontal (chicanes, pinch points) Off-set junctions (Local Streets) On-street car parking Vertical (ramps, tables) Long straights (>70m between junctions) Pedestrian crossings Entry treatments
DMURS Practical Implications On-street parking and loading (4.4.9) Functions Commercial viability of centres Calm traffic Reduce parking on footpaths
DMURS Practical Implications What Networks will look like Permeable neighbourhoods More pedestrian crossings No more distributor roads with high walls Inner Relief Roads - retain place function Outer Relief Roads - outside urban area Some level of car congestion
DMURS Practical Implications What Streets will look like Narrower carriageways, wider footpaths Tighter corner radii Shorter cycle times at signals Avoid left turn slip roads at junctions No large roundabouts Avoid pedestrian guardrails Less signing and lining More on-street parking
Fundamental Message Design urban roads and streets for all users People using them for transport People using them as a place to live
Fundamental Message A better balance between the and the Place Function Transport Function of urban roads and streets